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Essentials of Statistics for Business and Economics 6th Edition By David R. Anderson – Test Bank
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CHAPTER 2—DESCRIPTIVE STATISTICS: TABULAR AND GRAPHICAL PRESENTATIONS
MULTIPLE CHOICE
- A frequency distribution is a tabular summary of data showing the
| a. | fraction of items in several classes |
| b. | percentage of items in several classes |
| c. | relative percentage of items in several classes |
| d. | number of items in several classes |
ANS: D PTS: 1 TOP: Descriptive Statistics
- A frequency distribution is
| a. | a tabular summary of a set of data showing the relative frequency |
| b. | a graphical form of representing data |
| c. | a tabular summary of a set of data showing the frequency of items in each of several nonoverlapping classes |
| d. | a graphical device for presenting categorical data |
ANS: C PTS: 1 TOP: Descriptive Statistics
- A tabular summary of a set of data showing the fraction of the total number of items in several classes is a
| a. | frequency distribution |
| b. | relative frequency distribution |
| c. | frequency |
| d. | cumulative frequency distribution |
ANS: B PTS: 1 TOP: Descriptive Statistics
- The relative frequency of a class is computed by
| a. | dividing the midpoint of the class by the sample size |
| b. | dividing the frequency of the class by the midpoint |
| c. | dividing the sample size by the frequency of the class |
| d. | dividing the frequency of the class by the sample size |
ANS: D PTS: 1 TOP: Descriptive Statistics
- The percent frequency of a class is computed by
| a. | multiplying the relative frequency by 10 |
| b. | dividing the relative frequency by 100 |
| c. | multiplying the relative frequency by 100 |
| d. | adding 100 to the relative frequency |
ANS: C PTS: 1 TOP: Descriptive Statistics
- The sum of frequencies for all classes will always equal
| a. | 1 |
| b. | the number of elements in a data set |
| c. | the number of classes |
| d. | a value between 0 and 1 |
ANS: B PTS: 1 TOP: Descriptive Statistics
- Fifteen percent of the students in a school of Business Administration are majoring in Economics, 20% in Finance, 35% in Management, and 30% in Accounting. The graphical device(s) which can be used to present these data is (are)
| a. | a line chart |
| b. | only a bar chart |
| c. | only a pie chart |
| d. | both a bar chart and a pie chart |
ANS: D PTS: 1 TOP: Descriptive Statistics
- A researcher is gathering data from four geographical areas designated: South = 1; North = 2; East = 3; West = 4. The designated geographical regions represent
| a. | categorical data |
| b. | quantitative data |
| c. | label data |
| d. | either quantitative or categorical data |
ANS: A PTS: 1 TOP: Descriptive Statistics
- Categorical data can be graphically represented by using a(n)
| a. | histogram |
| b. | frequency polygon |
| c. | ogive |
| d. | bar chart |
ANS: D PTS: 1 TOP: Descriptive Statistics
- A cumulative relative frequency distribution shows
| a. | the proportion of data items with values less than or equal to the upper limit of each class |
| b. | the proportion of data items with values less than or equal to the lower limit of each class |
| c. | the percentage of data items with values less than or equal to the upper limit of each class |
| d. | the percentage of data items with values less than or equal to the lower limit of each class |
ANS: A PTS: 1 TOP: Descriptive Statistics
- If several frequency distributions are constructed from the same data set, the distribution with the widest class width will have the
| a. | fewest classes |
| b. | most classes |
| c. | same number of classes as the other distributions since all are constructed from the same data |
ANS: A PTS: 1 TOP: Descriptive Statistics
- The sum of the relative frequencies for all classes will always equal
| a. | the sample size |
| b. | the number of classes |
| c. | one |
| d. | any value larger than one |
ANS: C PTS: 1 TOP: Descriptive Statistics
- The sum of the percent frequencies for all classes will always equal
| a. | one |
| b. | the number of classes |
| c. | the number of items in the study |
| d. | 100 |
ANS: D PTS: 1 TOP: Descriptive Statistics
- The most common graphical presentation of quantitative data is a
| a. | histogram |
| b. | bar chart |
| c. | relative frequency |
| d. | pie chart |
ANS: A PTS: 1 TOP: Descriptive Statistics
- The total number of data items with a value less than the upper limit for the class is given by the
| a. | frequency distribution |
| b. | relative frequency distribution |
| c. | cumulative frequency distribution |
| d. | cumulative relative frequency distribution |
ANS: C PTS: 1 TOP: Descriptive Statistics
- The relative frequency of a class is computed by
| a. | dividing the cumulative frequency of the class by n |
| b. | dividing n by cumulative frequency of the class |
| c. | dividing the frequency of the class by n |
| d. | dividing the frequency of the class by the number of classes |
ANS: C PTS: 1 TOP: Descriptive Statistics
- In constructing a frequency distribution, the approximate class width is computed as
| a. | (largest data value – smallest data value)/number of classes |
| b. | (largest data value – smallest data value)/sample size |
| c. | (smallest data value – largest data value)/sample size |
| d. | largest data value/number of classes |
ANS: A PTS: 1 TOP: Descriptive Statistics
- In constructing a frequency distribution, as the number of classes are decreased, the class width
| a. | decreases |
| b. | remains unchanged |
| c. | increases |
| d. | can increase or decrease depending on the data values |
ANS: C PTS: 1 TOP: Descriptive Statistics
- The difference between the lower class limits of adjacent classes provides the
| a. | number of classes |
| b. | class limits |
| c. | class midpoint |
| d. | class width |
ANS: D PTS: 1 TOP: Descriptive Statistics
- In a cumulative frequency distribution, the last class will always have a cumulative frequency equal to
| a. | one |
| b. | 100% |
| c. | the total number of elements in the data set |
| d. | None of these alternatives is correct. |
ANS: C PTS: 1 TOP: Descriptive Statistics
- In a cumulative relative frequency distribution, the last class will have a cumulative relative frequency equal to
| a. | one |
| b. | zero |
| c. | the total number of elements in the data set |
| d. | None of these alternatives is correct. |
ANS: A PTS: 1 TOP: Descriptive Statistics
- In a cumulative percent frequency distribution, the last class will have a cumulative percent frequency equal to
| a. | one |
| b. | 100 |
| c. | the total number of elements in the data set |
| d. | None of these alternatives is correct. |
ANS: B PTS: 1 TOP: Descriptive Statistics
- Data that provide labels or names for categories of like items are known as
| a. | categorical data |
| b. | quantitative data |
| c. | label data |
| d. | category data |
ANS: A PTS: 1 TOP: Descriptive Statistics
- A tabular method that can be used to summarize the data on two variables simultaneously is called
| a. | simultaneous equations |
| b. | crosstabulation |
| c. | a histogram |
| d. | an ogive |
ANS: B PTS: 1 TOP: Descriptive Statistics
- A graphical presentation of the relationship between two variables is
| a. | an ogive |
| b. | a histogram |
| c. | either an ogive or a histogram, depending on the type of data |
| d. | a scatter diagram |
ANS: D PTS: 1 TOP: Descriptive Statistics
- A histogram is said to be skewed to the left if it has a
| a. | longer tail to the right |
| b. | shorter tail to the right |
| c. | shorter tail to the left |
| d. | longer tail to the left |
ANS: D PTS: 1 TOP: Descriptive Statistics
- When a histogram has a longer tail to the right, it is said to be
| a. | symmetrical |
| b. | skewed to the left |
| c. | skewed to the right |
| d. | none of these alternatives is correct |
ANS: C PTS: 1 TOP: Descriptive Statistics
- In a scatter diagram, a line that provides an approximation of the relationship between the variables is known as
| a. | approximation line |
| b. | trend line |
| c. | line of zero intercept |
| d. | line of zero slope |
ANS: B PTS: 1 TOP: Descriptive Statistics
- A histogram is
| a. | a graphical presentation of a frequency or relative frequency distribution |
| b. | a graphical method of presenting a cumulative frequency or a cumulative relative frequency distribution |
| c. | the history of data elements |
| d. | the same as a pie chart |
ANS: A PTS: 1 TOP: Descriptive Statistics
- A situation in which conclusions based upon aggregated crosstabulation are different from unaggregated crosstabulation is known as
| a. | wrong crosstabulation |
| b. | Simpson’s rule |
| c. | Simpson’s paradox |
| d. | aggregated crosstabulation |
ANS: C PTS: 1 TOP: Descriptive Statistics
Exhibit 2-1
The numbers of hours worked (per week) by 400 statistics students are shown below.
| Number of hours | Frequency |
| 0 – 9 | 20 |
| 10 – 19 | 80 |
| 20 – 29 | 200 |
| 30 – 39 | 100 |
- Refer to Exhibit 2-1. The class width for this distribution
| a. | is 9 |
| b. | is 10 |
| c. | is 39, which is: the largest value minus the smallest value or 39 – 0 = 39 |
| d. | varies from class to class |
ANS: B PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-1. The number of students working 19 hours or less
| a. | is 80 |
| b. | is 100 |
| c. | is 180 |
| d. | is 300 |
ANS: B PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-1. The relative frequency of students working 9 hours or less
| a. | is 20 |
| b. | is 100 |
| c. | is 0.95 |
| d. | 0.05 |
ANS: D PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-1. The percentage of students working 19 hours or less is
| a. | 20% |
| b. | 25% |
| c. | 75% |
| d. | 80% |
ANS: B PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-1. The cumulative relative frequency for the class of 20 – 29
| a. | is 300 |
| b. | is 0.25 |
| c. | is 0.75 |
| d. | is 0.5 |
ANS: C PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-1. The cumulative percent frequency for the class of 30 – 39 is
| a. | 100% |
| b. | 75% |
| c. | 50% |
| d. | 25% |
ANS: A PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-1. The cumulative frequency for the class of 20 – 29
| a. | is 200 |
| b. | is 300 |
| c. | is 0.75 |
| d. | is 0.5 |
ANS: B PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-1. If a cumulative frequency distribution is developed for the above data, the last class will have a cumulative frequency of
| a. | 100 |
| b. | 1 |
| c. | 30 – 39 |
| d. | 400 |
ANS: D PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-1. The percentage of students who work at least 10 hours per week is
| a. | 50% |
| b. | 5% |
| c. | 95% |
| d. | 100% |
ANS: C PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-1. The number of students who work 19 hours or less is
| a. | 80 |
| b. | 100 |
| c. | 200 |
| d. | 400 |
ANS: B PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-1. The midpoint of the last class is
| a. | 50 |
| b. | 34 |
| c. | 35 |
| d. | 34.5 |
ANS: D PTS: 1 TOP: Descriptive Statistics
Exhibit 2-2
A survey of 800 college seniors resulted in the following crosstabulation regarding their undergraduate major and whether or not they plan to go to graduate school.
| Undergraduate Major | ||||
| Graduate School | Business | Engineering | Others | Total |
| Yes | 70 | 84 | 126 | 280 |
| No | 182 | 208 | 130 | 520 |
| Total | 252 | 292 | 256 | 800 |
- Refer to Exhibit 2-2. What percentage of the students does not plan to go to graduate school?
| a. | 280 |
| b. | 520 |
| c. | 65 |
| d. | 32 |
ANS: C PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-2. What percentage of the students’ undergraduate major is engineering?
| a. | 292 |
| b. | 520 |
| c. | 65 |
| d. | 36.5 |
ANS: D PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-2. Of those students who are majoring in business, what percentage plans to go to graduate school?
| a. | 27.78 |
| b. | 8.75 |
| c. | 70 |
| d. | 72.22 |
ANS: A PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-2. Among the students who plan to go to graduate school, what percentage indicated “Other” majors?
| a. | 15.75 |
| b. | 45 |
| c. | 54 |
| d. | 35 |
ANS: B PTS: 1 TOP: Descriptive Statistics
Exhibit 2-3
Michael’s Compute-All, a national computer retailer, has kept a record of the number of laptop computers they have sold for a period of 80 days. Their sales records are shown below:
Number of Laptops Sold Number of Days
0 – 19 5
20 – 39 15
40 – 59 30
60 – 79 20
80 – 99 10
Total 80
- Refer to Exhibit 2-3. The class width of the above distribution is
| a. | 0 to 100 |
| b. | 20 |
| c. | 80 |
| d. | 5 |
ANS: B PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-3. The lower limit of the first class is
| a. | 5 |
| b. | 80 |
| c. | 0 |
| d. | 20 |
ANS: C PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-3. If one develops a cumulative frequency distribution for the above data, the last class will have a frequency of
| a. | 10 |
| b. | 100 |
| c. | 0 to 100 |
| d. | 80 |
ANS: D PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-3. The percentage of days in which the company sold at least 40 laptops is
| a. | 37.5% |
| b. | 62.5% |
| c. | 90.0% |
| d. | 75.0% |
ANS: D PTS: 1 TOP: Descriptive Statistics
- Refer to Exhibit 2-3. The number of days in which the company sold less than 60 laptops is
| a. | 20 |
| b. | 30 |
| c. | 50 |
| d. | 60 |
ANS: C PTS: 1 TOP: Descriptive Statistics
PROBLEM
- Thirty students in the School of Business were asked what their majors were. The following represents their responses (M = Management; A = Accounting; E = Economics; O = Others).
| A | M | M | A | M | M | E | M | O | A |
| E | E | M | A | O | E | M | A | M | A |
| M | A | O | A | M | E | E | M | A | M |
| a. | Construct a frequency distribution and a bar chart. |
| b. | Construct a relative frequency distribution and a pie chart. |
ANS:
| (a) | (b) | |
|
Major |
Frequency |
Relative
Frequency |
| M | 12 | 0.4 |
| A | 9 | 0.3 |
| E | 6 | 0.2 |
| O | 3 | 0.1 |
| Total | 30 | 1.0 |
PTS: 1 TOP: Descriptive Statistics
- Twenty employees of the Ahmadi Corporation were asked if they liked or disliked the new district manager. Below you are given their responses. Let L represent liked and D represent disliked.
| L | L | D | L | D |
| D | D | L | L | D |
| D | L | D | D | L |
| D | D | L | D | L |
| a. | Construct a frequency distribution and a bar chart. |
| b. | Construct a relative frequency distribution and a pie chart. |
ANS:
a and b
|
Preferences |
Frequency |
Relative
Frequency |
| L | 9 | 0.45 |
| D | 11 | 0.55 |
| Total | 20 | 1.00 |
PTS: 1 TOP: Descriptive Statistics
- Forty shoppers were asked if they preferred the weight of a can of soup to be 6 ounces, 8 ounces, or 10 ounces. Below you are given their responses.
| 6 | 6 | 6 | 10 | 8 | 8 | 8 | 10 | 6 | 6 |
| 10 | 10 | 8 | 8 | 6 | 6 | 6 | 8 | 6 | 6 |
| 8 | 8 | 8 | 10 | 8 | 8 | 6 | 10 | 8 | 6 |
| 6 | 8 | 8 | 8 | 10 | 10 | 8 | 10 | 8 | 6 |
| a. | Construct a frequency distribution and graphically represent the frequency distribution. |
| b. | Construct a relative frequency distribution and graphically represent the relative frequency distribution. |
ANS:
a and b
|
Preferences |
Frequency |
Relative
Frequency |
| 6 ounces | 14 | 0.350 |
| 8 ounces | 17 | 0.425 |
| 10 ounces | 9 | 0.225 |
| Total | 40 | 1.000 |
PTS: 1 TOP: Descriptive Statistics
- A student has completed 20 courses in the School of Arts and Sciences. Her grades in the 20 courses are shown below.
| A | B | A | B | C |
| C | C | B | B | B |
| B | A | B | B | B |
| C | B | C | B | A |
| a. | Develop a frequency distribution and a bar chart for her grades. |
| b. | Develop a relative frequency distribution for her grades and construct a pie chart. |
ANS:
a and b
|
Grade |
Frequency |
Relative
Frequency |
| A | 4 | 0.20 |
| B | 11 | 0.55 |
| C | 5 | 0.25 |
| Total | 20 | 1.00 |
PTS: 1 TOP: Descriptive Statistics
- A sample of 50 TV viewers were asked, “Should TV sponsors pull their sponsorship from programs that draw numerous viewer complaints?” Below are the results of the survey. (Y = Yes; N = No; W = Without Opinion)
| N | W | N | N | Y | N | N | N | Y | N |
| N | Y | N | N | N | N | N | Y | N | N |
| Y | N | Y | W | N | Y | W | W | N | Y |
| W | W | N | W | Y | W | N | W | Y | W |
| N | Y | N | Y | N | W | Y | Y | N | Y |
| a. | Construct a frequency distribution and a bar chart. |
| b. | Construct a relative frequency distribution and a pie chart. |
ANS:
a and b
|
Frequency |
Relative
Frequency |
|
| No | 24 | 0.48 |
| Yes | 15 | 0.30 |
| Without Opinion | 11 | 0.22 |
| Total | 50 | 1.00 |
PTS: 1 TOP: Descriptive Statistics
- Below you are given the examination scores of 20 students.
| 52 | 99 | 92 | 86 | 84 |
| 63 | 72 | 76 | 95 | 88 |
| 92 | 58 | 65 | 79 | 80 |
| 90 | 75 | 74 | 56 | 99 |
| a. | Construct a frequency distribution for this data. Let the first class be 50 – 59 and draw a histogram. |
| b. | Construct a cumulative frequency distribution. |
| c. | Construct a relative frequency distribution. |
| d. | Construct a cumulative relative frequency distribution. |
ANS:
| a. | b. | c. | d. | |
| Cumulative | ||||
| Cumulative | Relative | Relative | ||
| Score | Frequency | Frequency | Frequency | Frequency |
| 50 – 59 | 3 | 3 | 0.15 | 0.15 |
| 60 – 69 | 2 | 5 | 0.10 | 0.25 |
| 70 – 79 | 5 | 10 | 0.25 | 0.50 |
| 80 – 89 | 4 | 14 | 0.20 | 0.70 |
| 90 – 99 | 6 | 20 | 0.30 | 1.00 |
| Total | 20 | 1.00 |
PTS: 1 TOP: Descriptive Statistics
- The frequency distribution below was constructed from data collected from a group of 25 students.
| Height
(in Inches) |
Frequency |
| 58 – 63 | 3 |
| 64 – 69 | 5 |
| 70 – 75 | 2 |
| 76 – 81 | 6 |
| 82 – 87 | 4 |
| 88 – 93 | 3 |
| 94 – 99 | 2 |
| a. | Construct a relative frequency distribution. |
| b. | Construct a cumulative frequency distribution. |
| c. | Construct a cumulative relative frequency distribution. |
ANS:
| a. | b. | c. | ||
| Cumulative | ||||
| Height | Relative | Cumulative | Relative | |
| (In Inches) | Frequency | Frequency | Frequency | Frequency |
| 58 – 63 | 3 | 0.12 | 3 | 0.12 |
| 64 – 69 | 5 | 0.20 | 8 | 0.32 |
| 70 – 75 | 2 | 0.08 | 10 | 0.40 |
| 76 – 81 | 6 | 0.24 | 16 | 0.64 |
| 82 – 87 | 4 | 0.16 | 20 | 0.80 |
| 88 – 93 | 3 | 0.12 | 23 | 0.92 |
| 94 – 99 | 2 | 0.08 | 25 | 1.00 |
| 1.00 |
PTS: 1 TOP: Descriptive Statistics
- The frequency distribution below was constructed from data collected on the quarts of soft drinks consumed per week by 20 students.
| Quarts of
Soft Drink |
Frequency |
| 0 – 3 | 4 |
| 4 – 7 | 5 |
| 8 – 11 | 6 |
| 12 – 15 | 3 |
| 16 – 19 | 2 |
| a. | Construct a relative frequency distribution. |
| b. | Construct a cumulative frequency distribution. |
| c. | Construct a cumulative relative frequency distribution. |
ANS:
| a. | b. | c. | ||
| Cumulative | ||||
| Quarts of | Relative | Cumulative | Relative | |
| Soft Drinks | Frequency | Frequency | Frequency | Frequency |
| 0 – 4 | 4 | 0.20 | 4 | 0.20 |
| 4 – 8 | 5 | 0.25 | 9 | 0.45 |
| 8 – 12 | 6 | 0.30 | 15 | 0.75 |
| 12 – 16 | 3 | 0.15 | 18 | 0.90 |
| 16 – 20 | 2 | 0.10 | 20 | 1.00 |
| Total | 20 | 1.00 |
PTS: 1 TOP: Descriptive Statistics
- The grades of 10 students on their first management test are shown below.
| 94 | 61 | 96 | 66 | 92 |
| 68 | 75 | 85 | 84 | 78 |
| a. | Construct a frequency distribution. Let the first class be 60 – 69. |
| b. | Construct a cumulative frequency distribution. |
| c. | Construct a relative frequency distribution. |
ANS:
| a. | b. | c. | |
| Cumulative | Relative | ||
| Class | Frequency | Frequency | Frequency |
| 60 – 69 | 3 | 3 | 0.3 |
| 70 – 79 | 2 | 5 | 0.2 |
| 80 – 89 | 2 | 7 | 0.2 |
| 90 – 99 | 3 | 10 | 0.3 |
| Total | 10 | 1.0 |
PTS: 1 TOP: Descriptive Statistics
- There are 800 students in the School of Business Administration. There are four majors in the School: Accounting, Finance, Management, and Marketing. The following shows the number of students in each major.
| Major | Number of Students |
| Accounting | 240 |
| Finance | 160 |
| Management | 320 |
| Marketing | 80 |
Develop a percent frequency distribution and construct a bar chart and a pie chart.
ANS:
| Major | Percent Frequency |
| Accounting | 30% |
| Finance | 20% |
| Management | 40% |
| Marketing | 10% |
PTS: 1 TOP: Descriptive Statistics
- You are given the following data on the ages of employees at a company. Construct a stem-and-leaf display.
| 26 | 32 | 28 | 45 | 58 |
| 52 | 44 | 36 | 42 | 27 |
| 41 | 53 | 55 | 48 | 32 |
| 42 | 44 | 40 | 36 | 37 |
ANS:
| 2 | 6 | 7 | 8 | |||||
| 3 | 2 | 2 | 6 | 6 | 7 | |||
| 4 | 0 | 1 | 2 | 2 | 4 | 4 | 5 | 8 |
| 5 | 2 | 3 | 5 | 8 |
PTS: 1 TOP: Descriptive Statistics
- Construct a stem-and-leaf display for the following data.
| 12 | 52 | 51 | 37 | 47 | 40 | 38 | 26 | 57 | 31 |
| 49 | 43 | 45 | 19 | 36 | 32 | 44 | 48 | 22 | 18 |
ANS:
| 1 | 2 | 8 | 9 | ||||
| 2 | 2 | 6 | |||||
| 3 | 1 | 2 | 6 | 7 | 8 | ||
| 4 | 0 | 3 | 4 | 5 | 7 | 8 | 9 |
| 5 | 1 | 2 | 7 |
PTS: 1 TOP: Descriptive Statistics
- The SAT scores of a sample of business school students and their genders are shown below.
| SAT Scores | ||||
| Gender | Less than 20 | 20 up to 25 | 25 and more | Total |
| Female | 24 | 168 | 48 | 240 |
| Male | 40 | 96 | 24 | 160 |
| Total | 64 | 264 | 72 | 400 |
| a. | How many students scored less than 20? |
| b. | How many students were female? |
| c. | Of the male students, how many scored 25 or more? |
| d. | Compute row percentages and comment on any relationship that may exist between SAT scores and gender of the individuals. |
| e. | Compute column percentages. |
ANS:
| a. | 64 | ||||
| b. | 240 | ||||
| c. | 24 | ||||
| d. | SAT Scores | ||||
| Gender | Less than 20 | 20 up to 25 | 25 and more | Total | |
| Female | 10% | 70% | 20% | 100% | |
| Male | 25% | 60% | 15% | 100% | |
| From the above percentages it can be noted that the largest percentages of both genders’ SAT scores are in the 20 to 25 range. However, 70% of females and only 60% of males have SAT scores in this range. Also it can be noted that 10% of females’ SAT scores are under 20, whereas, 25% of males’ SAT scores fall in this category. | |||||
| e. | SAT Scores | ||||
| Gender | Less than 20 | 20 up to 25 | 25 and more | ||
| Female | 37.5% | 63.6% | 66.7% | ||
| Male | 62.5% | 36.4% | 33.3% | ||
| Total | 100% | 100% | 100% | ||
PTS: 1 TOP: Descriptive Statistics
- For the following observations, plot a scatter diagram and indicate what kind of relationship (if any) exist between x and y.
| x | y |
| 2 | 7 |
| 6 | 19 |
| 3 | 9 |
| 5 | 17 |
| 4 | 11 |
ANS:
A positive relationship between x and y appears to exist.
CHAPTER 4—INTRODUCTION TO PROBABILITY
MULTIPLE CHOICE
- Each individual outcome of an experiment is called
| a. | the sample space |
| b. | a sample point |
| c. | an experiment |
| d. | an individual |
ANS: B PTS: 1 TOP: Probability Concepts
- The collection of all possible sample points in an experiment is
| a. | the sample space |
| b. | a sample point |
| c. | an experiment |
| d. | the population |
ANS: A PTS: 1 TOP: Probability Concepts
- A graphical method of representing the sample points of an experiment is
| a. | a frequency polygon |
| b. | a histogram |
| c. | an ogive |
| d. | a tree diagram |
ANS: D PTS: 1 TOP: Probability Concepts
- An experiment consists of selecting a student body president and vice president. All undergraduate students (freshmen through seniors) are eligible for these offices. How many sample points (possible outcomes as to the classifications) exist?
| a. | 4 |
| b. | 16 |
| c. | 8 |
| d. | 32 |
ANS: B PTS: 1 TOP: Probability Concepts
- Any process that generates well-defined outcomes is
| a. | an event |
| b. | an experiment |
| c. | a sample point |
| d. | a sample space |
ANS: B PTS: 1 TOP: Probability Concepts
- The sample space refers to
| a. | any particular experimental outcome |
| b. | the sample size minus one |
| c. | the set of all possible experimental outcomes |
| d. | an event |
ANS: C PTS: 1 TOP: Probability Concepts
- In statistical experiments, each time the experiment is repeated
| a. | the same outcome must occur |
| b. | the same outcome can not occur again |
| c. | a different outcome may occur |
| d. | a different out come must occur |
ANS: C PTS: 1 TOP: Probability Concepts
- When the assumption of equally likely outcomes is used to assign probability values, the method used to assign probabilities is referred to as the
| a. | relative frequency method |
| b. | subjective method |
| c. | probability method |
| d. | classical method |
ANS: D PTS: 1 TOP: Probability Concepts
- The counting rule that is used for counting the number of experimental outcomes when n objects are selected from a set of N objects where order of selection is not important is called
| a. | permutation |
| b. | combination |
| c. | multiple step experiment |
| d. | None of these alternatives is correct. |
ANS: B PTS: 1 TOP: Probability Concepts
- The counting rule that is used for counting the number of experimental outcomes when n objects are selected from a set of N objects where order of selection is important is called
| a. | permutation |
| b. | combination |
| c. | multiple step experiment |
| d. | None of these alternatives is correct. |
ANS: A PTS: 1 TOP: Probability Concepts
- From a group of six people, two individuals are to be selected at random. How many possible selections are there?
| a. | 12 |
| b. | 36 |
| c. | 15 |
| d. | 8 |
ANS: C PTS: 1 TOP: Probability Concepts
- When the results of experimentation or historical data are used to assign probability values, the method used to assign probabilities is referred to as the
| a. | relative frequency method |
| b. | subjective method |
| c. | classical method |
| d. | posterior method |
ANS: A PTS: 1 TOP: Probability Concepts
- A method of assigning probabilities based upon judgment is referred to as the
| a. | relative method |
| b. | probability method |
| c. | classical method |
| d. | subjective method |
ANS: D PTS: 1 TOP: Probability Concepts
- A sample point refers to the
| a. | numerical measure of the likelihood of the occurrence of an event |
| b. | set of all possible experimental outcomes |
| c. | individual outcome of an experiment |
| d. | sample space |
ANS: C PTS: 1 TOP: Probability Concepts
- A graphical device used for enumerating sample points in a multiple-step experiment is a
| a. | bar chart |
| b. | pie chart |
| c. | histogram |
| d. | None of these alternatives is correct. |
ANS: D PTS: 1 TOP: Probability Concepts
- The intersection of two mutually exclusive events
| a. | can be any value between 0 to 1 |
| b. | must always be equal to 1 |
| c. | must always be equal to 0 |
| d. | can be any positive value |
ANS: C PTS: 1 TOP: Probability Concepts
- Two events are mutually exclusive
| a. | if their intersection is 1 |
| b. | if they have no sample points in common |
| c. | if their intersection is 0.5 |
| d. | None of these alternatives is correct. |
ANS: B PTS: 1 TOP: Probability Concepts
- The range of probability is
| a. | any value larger than zero |
| b. | any value between minus infinity to plus infinity |
| c. | zero to one |
| d. | any value between -1 to 1 |
ANS: C PTS: 1 TOP: Probability Concepts
- Which of the following statements is always true?
| a. | -1 P(Ei) 1 |
| b. | P(A) = 1 – P(Ac) |
| c. | P(A) + P(B) = 1 |
| d. | åP 1 |
ANS: B PTS: 1 TOP: Probability Concepts
- Events that have no sample points in common are
| a. | independent events |
| b. | posterior events |
| c. | mutually exclusive events |
| d. | complements |
ANS: C PTS: 1 TOP: Probability Concepts
- Initial estimates of the probabilities of events are known as
| a. | sets |
| b. | posterior probabilities |
| c. | conditional probabilities |
| d. | prior probabilities |
ANS: D PTS: 1 TOP: Probability Concepts
- Two events with nonzero probabilities
| a. | can be both mutually exclusive and independent |
| b. | can not be both mutually exclusive and independent |
| c. | are always mutually exclusive |
| d. | are always independent |
ANS: B PTS: 1 TOP: Probability Concepts
- Two events, A and B, are mutually exclusive and each have a nonzero probability. If event A is known to occur, the probability of the occurrence of event B is
| a. | one |
| b. | any positive value |
| c. | zero |
| d. | any value between 0 to 1 |
ANS: C PTS: 1 TOP: Probability Concepts
- The addition law is potentially helpful when we are interested in computing the probability of
| a. | independent events |
| b. | the intersection of two events |
| c. | the union of two events |
| d. | conditional events |
ANS: C PTS: 1 TOP: Probability Concepts
- The sum of the probabilities of two complementary events is
| a. | Zero |
| b. | 0.5 |
| c. | 0.57 |
| d. | 1.0 |
ANS: D PTS: 1 TOP: Probability Concepts
- Events A and B are mutually exclusive if their joint probability is
| a. | larger than 1 |
| b. | less than zero |
| c. | zero |
| d. | infinity |
ANS: C PTS: 1 TOP: Probability Concepts
- The set of all possible outcomes of an experiment is
| a. | an experiment |
| b. | an event |
| c. | the population |
| d. | the sample space |
ANS: D PTS: 1 TOP: Probability Concepts
- Assuming that each of the 52 cards in an ordinary deck has a probability of 1/52 of being drawn, what is the probability of drawing a black ace?
| a. | 1/52 |
| b. | 2/52 |
| c. | 3/52 |
| d. | 4/52 |
ANS: B PTS: 1 TOP: Probability Concepts
- If a dime is tossed four times and comes up tails all four times, the probability of heads on the fifth trial is
| a. | smaller than the probability of tails |
| b. | larger than the probability of tails |
| c. | 1/2 |
| d. | 1/32 |
ANS: C PTS: 1 TOP: Probability Concepts
- If a six sided die is tossed two times and “3” shows up both times, the probability of “3” on the third trial is
| a. | much larger than any other outcome |
| b. | much smaller than any other outcome |
| c. | 1/6 |
| d. | 1/216 |
ANS: C PTS: 1 TOP: Probability Concepts
- If A and B are independent events with P(A) = 0.65 and P(A Ç B) = 0.26, then, P(B) =
| a. | 0.400 |
| b. | 0.169 |
| c. | 0.390 |
| d. | 0.650 |
ANS: A PTS: 1 TOP: Probability Concepts
- If P(A) = 0.4, P(B | A) = 0.35, P(A È B) = 0.69, then P(B) =
| a. | 0.14 |
| b. | 0.43 |
| c. | 0.75 |
| d. | 0.59 |
ANS: B PTS: 1 TOP: Probability Concepts
- Of five letters (A, B, C, D, and E), two letters are to be selected at random. How many possible selections are there?
| a. | 20 |
| b. | 7 |
| c. | 5! |
| d. | 10 |
ANS: D PTS: 1 TOP: Probability Concepts
- Given that event E has a probability of 0.31, the probability of the complement of event E
| a. | cannot be determined with the above information |
| b. | can have any value between zero and one |
| c. | 0.69 |
| d. | is 0.31 |
ANS: C PTS: 1 TOP: Probability Concepts
- Three applications for admission to a local university are checked, and it is determined whether each applicant is male or female. The number of sample points in this experiment is
| a. | 2 |
| b. | 4 |
| c. | 6 |
| d. | 8 |
ANS: D PTS: 1 TOP: Probability Concepts
- Assume your favorite football team has 2 games left to finish the season. The outcome of each game can be win, lose or tie. The number of possible outcomes is
| a. | 2 |
| b. | 4 |
| c. | 6 |
| d. | 9 |
ANS: D PTS: 1 TOP: Probability Concepts
- Each customer entering a department store will either buy or not buy some merchandise. An experiment consists of following 3 customers and determining whether or not they purchase any merchandise. The number of sample points in this experiment is
| a. | 2 |
| b. | 4 |
| c. | 6 |
| d. | 8 |
ANS: D PTS: 1 TOP: Probability Concepts
- An experiment consists of tossing 4 coins successively. The number of sample points in this experiment is
| a. | 16 |
| b. | 8 |
| c. | 4 |
| d. | 2 |
ANS: A PTS: 1 TOP: Probability Concepts
- An experiment consists of three steps. There are four possible results on the first step, three possible results on the second step, and two possible results on the third step. The total number of experimental outcomes is
| a. | 9 |
| b. | 14 |
| c. | 24 |
| d. | 36 |
ANS: C PTS: 1 TOP: Probability Concepts
- Since the sun must rise tomorrow, then the probability of the sun rising tomorrow is
| a. | much larger than one |
| b. | zero |
| c. | infinity |
| d. | None of these alternatives is correct. |
ANS: D PTS: 1 TOP: Probability Concepts
- If two events are independent, then
| a. | they must be mutually exclusive |
| b. | the sum of their probabilities must be equal to one |
| c. | their intersection must be zero |
| d. | None of these alternatives is correct. |
ANS: D PTS: 1 TOP: Probability Concepts
- Bayes’ theorem is used to compute
| a. | the prior probabilities |
| b. | the union of events |
| c. | intersection of events |
| d. | the posterior probabilities |
ANS: D PTS: 1 TOP: Probability Concepts
- On a December day, the probability of snow is .30. The probability of a “cold” day is .50. The probability of snow and “cold” weather is .15. Are snow and “cold” weather independent events?
| a. | only if given that it snowed |
| b. | no |
| c. | yes |
| d. | only when they are also mutually exclusive |
ANS: C PTS: 1 TOP: Probability Concepts
- One of the basic requirements of probability is
| a. | for each experimental outcome Ei, we must have P(Ei) 1 |
| b. | P(A) = P(Ac) – 1 |
| c. | if there are k experimental outcomes, then åP(Ei) = 1 |
| d. | åP(Ei) 1 |
ANS: C PTS: 1 TOP: Probability Concepts
- The symbol Ç shows the
| a. | union of events |
| b. | intersection of two events |
| c. | sum of the probabilities of events |
| d. | sample space |
ANS: B PTS: 1 TOP: Probability Concepts
- The symbol È shows the
| a. | union of events |
| b. | intersection of two events |
| c. | sum of the probabilities of events |
| d. | sample space |
ANS: A PTS: 1 TOP: Probability Concepts
- The multiplication law is potentially helpful when we are interested in computing the probability of
| a. | mutually exclusive events |
| b. | the intersection of two events |
| c. | the union of two events |
| d. | conditional events |
ANS: B PTS: 1 TOP: Probability Concepts
- If two events are mutually exclusive, then their intersection
| a. | will be equal to zero |
| b. | can have any value larger than zero |
| c. | must be larger than zero, but less than one |
| d. | will be one |
ANS: A PTS: 1 TOP: Probability Concepts
- The union of events A and B is the event containing
| a. | all the sample points belonging to B or A |
| b. | all the sample points belonging to A or B |
| c. | all the sample points belonging to A or B or both |
| d. | all the sample points belonging to A or B, but not both |
ANS: C PTS: 1 TOP: Probability Concepts
- If a penny is tossed three times and comes up heads all three times, the probability of heads on the fourth trial is
| a. | zero |
| b. | 1/16 |
| c. | 1/2 |
| d. | larger than the probability of tails |
ANS: C PTS: 1 TOP: Probability Concepts
- If a coin is tossed three times, the likelihood of obtaining three heads in a row is
| a. | zero |
| b. | 0.500 |
| c. | 0.875 |
| d. | 0.125 |
ANS: D PTS: 1 TOP: Probability Concepts
- The union of two events with nonzero probabilities
| a. | cannot be less than one |
| b. | cannot be one |
| c. | could be larger than one |
| d. | None of these alternatives is correct. |
ANS: D PTS: 1 TOP: Probability Concepts
- If P(A) = 0.5 and P(B) = 0.5, then P(A Ç B)
| a. | is 0.00 |
| b. | is 1.00 |
| c. | is 0.5 |
| d. | None of these alternatives is correct. |
ANS: D PTS: 1 TOP: Probability Concepts
- If A and B are independent events with P(A) = 0.4 and P(B) = 0.6, then P(A Ç B) =
| a. | 0.76 |
| b. | 1.00 |
| c. | 0.24 |
| d. | 0.20 |
ANS: C PTS: 1 TOP: Probability Concepts
- If A and B are independent events with P(A) = 0.2 and P(B) = 0.6, then P(A È B) =
| a. | 0.62 |
| b. | 0.12 |
| c. | 0.60 |
| d. | 0.68 |
ANS: D PTS: 1 TOP: Probability Concepts
- If A and B are independent events with P(A) = 0.05 and P(B) = 0.65, then P(A ½ B) =
| a. | 0.05 |
| b. | 0.0325 |
| c. | 0.65 |
| d. | 0.8 |
ANS: A PTS: 1 TOP: Probability Concepts
- If A and B are mutually exclusive events with P(A) = 0.3 and P(B) = 0.5, then P(A Ç B) =
| a. | 0.30 |
| b. | 0.15 |
| c. | 0.00 |
| d. | 0.20 |
ANS: C PTS: 1 TOP: Probability Concepts
- If A and B are mutually exclusive events with P(A) = 0.3 and P(B) = 0.5, then P(A È B) =
| a. | 0.00 |
| b. | 0.15 |
| c. | 0.8 |
| d. | 0.2 |
ANS: C PTS: 1 TOP: Probability Concepts
- A lottery is conducted using three urns. Each urn contains chips numbered from 0 to 9. One chip is selected at random from each urn. The total number of sample points in the sample space is
| a. | 30 |
| b. | 100 |
| c. | 729 |
| d. | 1,000 |
ANS: D PTS: 1 TOP: Probability Concepts
- Of the last 100 customers entering a computer shop, 25 have purchased a computer. If the classical method for computing probability is used, the probability that the next customer will purchase a computer is
| a. | 0.25 |
| b. | 0.50 |
| c. | 1.00 |
| d. | 0.75 |
ANS: B PTS: 1 TOP: Probability Concepts
- Events A and B are mutually exclusive with P(A) = 0.3 and P(B) = 0.2. Then, P(Bc) =
| a. | 0.00 |
| b. | 0.06 |
| c. | 0.7 |
| d. | 0.8 |
ANS: D PTS: 1 TOP: Probability Concepts
- An experiment consists of four outcomes with P(E1) = 0.2, P(E2) = 0.3, and P(E3) = 0.4. The probability of outcome E4 is
| a. | 0.500 |
| b. | 0.024 |
| c. | 0.100 |
| d. | 0.900 |
ANS: C PTS: 1 TOP: Probability Concepts
- Events A and B are mutually exclusive. Which of the following statements is also true?
| a. | A and B are also independent. |
| b. | P(A È B) = P(A)P(B) |
| c. | P(A È B) = P(A) + P(B) |
| d. | P(A Ç B) = P(A) + P(B) |
ANS: C PTS: 1 TOP: Probability Concepts
- A six-sided die is tossed 3 times. The probability of observing three ones in a row is
| a. | 1/3 |
| b. | 1/6 |
| c. | 1/27 |
| d. | 1/216 |
ANS: D PTS: 1 TOP: Probability Concepts
- The probability of the occurrence of event A in an experiment is 1/3. If the experiment is performed 2 times and event A did not occur, then on the third trial event A
| a. | must occur |
| b. | may occur |
| c. | could not occur |
| d. | has a 2/3 probability of occurring |
ANS: B PTS: 1 TOP: Probability Concepts
- A perfectly balanced coin is tossed 6 times and tails appears on all six tosses. Then, on the seventh trial
| a. | tails can not appear |
| b. | heads has a larger chance of appearing than tails |
| c. | tails has a better chance of appearing than heads |
| d. | None of these alternatives is correct. |
ANS: D PTS: 1 TOP: Probability Concepts
- In an experiment, events A and B are mutually exclusive. If P(A) = 0.6, then the probability of B
| a. | cannot be larger than 0.4 |
| b. | can be any value greater than 0.6 |
| c. | can be any value between 0 to 1 |
| d. | cannot be determined with the information given |
ANS: A PTS: 1 TOP: Probability Concepts
- The set of all possible sample points (experimental outcomes) is called
| a. | a sample |
| b. | an event |
| c. | the sample space |
| d. | a population |
ANS: C PTS: 1 TOP: Probability Concepts
- A method of assigning probabilities which assumes that the experimental outcomes are equally likely is referred to as the
| a. | objective method |
| b. | classical method |
| c. | subjective method |
| d. | experimental method |
ANS: B PTS: 1 TOP: Probability Concepts
- A method of assigning probabilities based on historical data is called the
| a. | classical method |
| b. | subjective method |
| c. | relative frequency method |
| d. | historical method |
ANS: C PTS: 1 TOP: Probability Concepts
- The probability assigned to each experimental outcome must be
| a. | any value larger than zero |
| b. | smaller than zero |
| c. | at least one |
| d. | between zero and one |
ANS: D PTS: 1 TOP: Probability Concepts
- If P(A) = 0.58, P(B) = 0.44, and P(A Ç B) = 0.25, then P(A È B) =
| a. | 1.02 |
| b. | 0.77 |
| c. | 0.11 |
| d. | 0.39 |
ANS: B PTS: 1 TOP: Probability Concepts
- If P(A) = 0.50, P(B) = 0.60, and P(A Ç B) = 0.30, then events A and B are
| a. | mutually exclusive events |
| b. | not independent events |
| c. | independent events |
| d. | not enough information is given to answer this question |
ANS: C PTS: 1 TOP: Probability Concepts
- If P(A) = 0.62, P(B) = 0.47, and P(A È B) = 0.88, then P(A Ç B) =
| a. | 0.2914 |
| b. | 1.9700 |
| c. | 0.6700 |
| d. | 0.2100 |
ANS: D PTS: 1 TOP: Probability Concepts
- If P(A) = 0.68, P(A È B) = 0.91, and P(A Ç B) = 0.35, then P(B) =
| a. | 0.22 |
| b. | 0.09 |
| c. | 0.65 |
| d. | 0.58 |
ANS: D PTS: 1 TOP: Probability Concepts
- If A and B are independent events with P(A) = 0.4 and P(B) = 0.25, then P(A È B) =
| a. | 0.65 |
| b. | 0.55 |
| c. | 0.10 |
| d. | 0.75 |
ANS: B PTS: 1 TOP: Probability Concepts
- If a penny is tossed three times and comes up heads all three times, the probability of heads on the fourth trial is
| a. | smaller than the probability of tails |
| b. | larger than the probability of tails |
| c. | 1/16 |
| d. | 1/2 |
ANS: D PTS: 1 TOP: Probability Concepts
- If P(A) = 0.50, P(B) = 0.40, then, and P(A È B) = 0.88, then P(B ½ A) =
| a. | 0.02 |
| b. | 0.03 |
| c. | 0.04 |
| d. | 0.05 |
ANS: C PTS: 1 TOP: Probability Concepts
- If A and B are independent events with P(A) = 0.38 and P(B) = 0.55, then P(A ½ B) =
| a. | 0.209 |
| b. | 0.000 |
| c. | 0.550 |
| d. | 0.38 |
ANS: D PTS: 1 TOP: Probability Concepts
- If X and Y are mutually exclusive events with P(X) = 0.295, P(Y) = 0.32, then P(X ½ Y) =
| a. | 0.0944 |
| b. | 0.6150 |
| c. | 1.0000 |
| d. | 0.0000 |
ANS: D PTS: 1 TOP: Probability Concepts
- If a six sided die is tossed two times, the probability of obtaining two “4s” in a row is
| a. | 1/6 |
| b. | 1/36 |
| c. | 1/96 |
| d. | 1/216 |
ANS: B PTS: 1 TOP: Probability Concepts
- If A and B are independent events with P(A) = 0.35 and P(B) = 0.20, then, P(A È B) =
| a. | 0.07 |
| b. | 0.62 |
| c. | 0.55 |
| d. | 0.48 |
ANS: D PTS: 1 TOP: Probability Concepts
- If P(A) = 0.7, P(B) = 0.6, P(A Ç B) = 0, then events A and B are
| a. | not mutually exclusive |
| b. | mutually exclusive |
| c. | independent events |
| d. | complements of each other |
ANS: B PTS: 1 TOP: Probability Concepts
- If P(A) = 0.45, P(B) = 0.55, and P(A È B) = 0.78, then P(A ½ B) =
| a. | zero |
| b. | 0.45 |
| c. | 0.22 |
| d. | 0.40 |
ANS: D PTS: 1 TOP: Probability Concepts
- If P(A) = 0.48, P(A È B) = 0.82, and P(B) = 0.54, then P(A Ç B) =
| a. | 0.3936 |
| b. | 0.3400 |
| c. | 0.2000 |
| d. | 1.0200 |
ANS: C PTS: 1 TOP: Probability Concepts
- Some of the CDs produced by a manufacturer are defective. From the production line, 5 CDs are selected and inspected. How many sample points exist in this experiment?
| a. | 10 |
| b. | 25 |
| c. | 30 |
| d. | 32 |
ANS: D PTS: 1 TOP: Probability Concepts
- An experiment consists of selecting a student body president, vice president, and a treasurer. All undergraduate students, freshmen through seniors, are eligible for the offices. How many sample points (possible outcomes as to the classifications) exist?
| a. | 12 |
| b. | 16 |
| c. | 64 |
| d. | 100 |
ANS: C PTS: 1 TOP: Probability Concepts
- Six applications for admission to a local university are checked, and it is determined whether each applicant is male or female. How many sample points exist in the above experiment?
| a. | 64 |
| b. | 32 |
| c. | 16 |
| d. | 4 |
ANS: A PTS: 1 TOP: Probability Concepts
- Assume your favorite football team has 3 games left to finish the season. The outcome of each game can be win, lose, or tie. How many possible outcomes exist?
| a. | 7 |
| b. | 27 |
| c. | 36 |
| d. | 64 |
ANS: B PTS: 1 TOP: Probability Concepts
- Each customer entering a department store will either buy or not buy some merchandise. An experiment consists of following 4 customers and determining whether or not they purchase any merchandise. How many sample points exist in the above experiment? (Note that each customer is either a purchaser or non-purchaser.)
| a. | 2 |
| b. | 4 |
| c. | 12 |
| d. | 16 |
ANS: D PTS: 1 TOP: Probability Concepts
- From nine cards numbered 1 through 9, two cards are drawn. Consider the selection and classification of the cards as odd or even as an experiment. How many sample points are there for this experiment?
| a. | 2 |
| b. | 3 |
| c. | 4 |
| d. | 9 |
ANS: C PTS: 1 TOP: Probability Concepts
PROBLEM
- A college plans to interview 8 students for possible offer of graduate assistantships. The college has three assistantships available. How many groups of three can the college select?
ANS:
56
PTS: 1 TOP: Probability Concepts
- A student has to take 9 more courses before he can graduate. If none of the courses are prerequisite to others, how many groups of four courses can he select for the next semester?
ANS:
126
PTS: 1 TOP: Probability Concepts
- From among 8 students how many committees consisting of 3 students can be selected?
ANS:
56
PTS: 1 TOP: Probability Concepts
- From a group of seven finalists to a contest, three individuals are to be selected for the first and second and third places. Determine the number of possible selections.
ANS:
210
PTS: 1 TOP: Probability Concepts
- Ten individuals are candidates for positions of president, vice president of an organization. How many possibilities of selections exist?
ANS:
90
PTS: 1 TOP: Probability Concepts
- Assume you have applied for two jobs A and B. The probability that you get an offer for job A is 0.23. The probability of being offered job B is 0.19. The probability of getting at least one of the jobs is 0.38.
| a. | What is the probability that you will be offered both jobs? |
| b. | Are events A and B mutually exclusive? Why or why not? Explain. |
ANS:
| a. | 0.04 |
| b. | No, because P(A Ç B) ¹ 0 |
PTS: 1 TOP: Probability Concepts
- Assume you have applied for two scholarships, a Merit scholarship (M) and an Athletic scholarship (A). The probability that you receive an Athletic scholarship is 0.18. The probability of receiving both scholarships is 0.11. The probability of getting at least one of the scholarships is 0.3.
| a. | What is the probability that you will receive a Merit scholarship? |
| b. | Are events A and M mutually exclusive? Why or why not? Explain. |
| c. | Are the two events A, and M, independent? Explain, using probabilities. |
| d. | What is the probability of receiving the Athletic scholarship given that you have been awarded the Merit scholarship? |
| e. | What is the probability of receiving the Merit scholarship given that you have been awarded the Athletic scholarship? |
ANS:
| a. | 0.23 |
| b. | No, because P(A Ç M) ¹ 0 |
| c. | No, because P(A Ç M) ¹ P(A) P(M) |
| d. | 0.4783 |
| e. | 0.6111 |
PTS: 1 TOP: Probability Concepts
- A survey of a sample of business students resulted in the following information regarding the genders of the individuals and their selected major.
Selected Major
| Gender | Management | Marketing | Others | Total |
| Male
|
40 | 10 | 30 | 80 |
| Female
|
30 | 20 | 70 | 120 |
| Total | 70 | 30 | 100 | 200 |
| a. | What is the probability of selecting an individual who is majoring in Marketing? |
| b. | What is the probability of selecting an individual who is majoring in Management, given that the person is female? |
| c. | Given that a person is male, what is the probability that he is majoring in Management? |
| d. | What is the probability of selecting a male individual? |
ANS:
| a. | 0.15 |
| b. | 0.25 |
| c. | 0.50 |
| d. | 0.40 |
PTS: 1 TOP: Probability Concepts
- Sixty percent of the student body at UTC is from the state of Tennessee (T), 30% percent are from other states (O), and the remainder are international students (I). Twenty percent of students from Tennessee live in the dormitories, whereas, 50% of students from other states live in the dormitories. Finally, 80% of the international students live in the dormitories.
| a. | What percentage of UTC students live in the dormitories? |
| b. | Given that a student lives in the dormitory, what is the probability that she/he is an international student? |
| c. | Given that a student lives in the dormitory, what is the probability that she/he is from Tennessee? |
ANS:
| a. | 35% |
| b. | 0.2286 (rounded) |
| c. | 0.3429 (rounded) |
PTS: 1 TOP: Probability Concepts
- The probability of an economic decline in the year 2008 is 0.23. There is a probability of 0.64 that we will elect a republican president in the year 2008. If we elect a republican president, there is a 0.35 probability of an economic decline. Let “D” represent the event of an economic decline, and “R” represent the event of election of a Republican president.
| a. | Are “R” and “D” independent events? |
| b. | What is the probability of a Republican president and economic decline in the year 2008? |
| c. | If we experience an economic decline in the year 2008, what is the probability that there will a Republican president? |
| d. | What is the probability of economic decline or a Republican president in the year 2008? Hint: You want to find P(D È R). |
ANS:
| a. | No, because P(D) ¹ P(D ½ R) |
| b. | 0.224 |
| c. | 0.9739 |
| d. | 0.646 |
PTS: 1 TOP: Probability Concepts
- As a company manager for Claimstat Corporation there is a 0.40 probability that you will be promoted this year. There is a 0.72 probability that you will get a promotion, a raise, or both. The probability of getting a promotion and a raise is 0.25.
| a. | If you get a promotion, what is the probability that you will also get a raise? |
| b. | What is the probability that you will get a raise? |
| c. | Are getting a raise and being promoted independent events? Explain using probabilities. |
| d. | Are these two events mutually exclusive? Explain using probabilities. |
ANS:
| a. | 0.625 |
| b. | 0.57 |
| c. | No, because P(R) ¹ P(R ½ P) |
| d. | No, because P(R Ç P) ¹ 0 |
PTS: 1 TOP: Probability Concepts
- A company plans to interview 10 recent graduates for possible employment. The company has three positions open. How many groups of three can the company select?
ANS:
120
PTS: 1 TOP: Probability Concepts
- A student has to take 7 more courses before she can graduate. If none of the courses are prerequisites to others, how many groups of three courses can she select for the next semester?
ANS:
35
PTS: 1 TOP: Probability Concepts
- How many committees, consisting of 3 female and 5 male students, can be selected from a group of 5 female and 8 male students?
ANS:
560
PTS: 1 TOP: Probability Concepts
- Six vitamin and three sugar tablets identical in appearance are in a box. One tablet is taken at random and given to Person A. A tablet is then selected and given to Person B. What is the probability that
| a. | Person A was given a vitamin tablet? |
| b. | Person B was given a sugar tablet given that Person A was given a vitamin tablet? |
| c. | neither was given vitamin tablets? |
| d. | both were given vitamin tablets? |
| e. | exactly one person was given a vitamin tablet? |
| f. | Person A was given a sugar tablet and Person B was given a vitamin tablet? |
| g. | Person A was given a vitamin tablet and Person B was given a sugar tablet? |
ANS:
| a. | 6/9 |
| b. | 3/8 |
| c. | 1/12 |
| d. | 5/12 |
| e. | 1/2 |
| f. | 1/4 |
| g. | 1/4 |
PTS: 1 TOP: Probability Concepts
- The sales records of a real estate agency show the following sales over the past 200 days:
| Number of | Number |
| Houses Sold | of Days |
| 0 | 60 |
| 1 | 80 |
| 2 | 40 |
| 3 | 16 |
| 4 | 4 |
| a. | How many sample points are there? |
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