BUS 223 Lecture Notes - Lecture 4: Cumulative Frequency Analysis, Frequency Distribution, Skewness
25 Jun 2018
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PRACTICE TEST #1
1. . A company has developed a new computer microprocessor whose average lifetime is unknown. In order
to estimate this average, 300 microprocessors are randomly selected from a large production line and
tested; their average lifetime is found to be 7 years. The 300 microprocessors represent a:
a. parameter.
b. statistic.
c. sample.
d. population.
2.A councilman who is running for the office of senator of a state with 3.5 million registered voters
commissions a survey. In the survey, 46% of the 8,000 registered voters interviewed say they plan to vote
for him. The population of interest is:
a. the 3.5 million registered voters in the state.
b. the 8,000 registered voters interviewed.
c. the 46% who plan to vote for her.
d. all the residents of the state.
3.. The process of using sample statistics to draw conclusions about population parameters is called:
a. finding the significance level.
b. calculating descriptive statistics.
c. doing inferential statistics.
d. calculating the confidence level.
4. A study is under way to determine the average height of all 63,000 adult walnut trees in a certain national
forest. The heights of 950 randomly selected adult walnut trees are measured and analyzed. The sample in
this study is:
a. the average height of the 950 randomly selected adult walnut trees.
b. the average height of all the adult walnut trees in this forest.
c. all the adult walnut trees in this forest.
d. the 950 adult walnut trees selected at random from this forest.
5..The classification of student major (accounting, economics, management, marketing, other) is an example
of a(n)
a. nominal random variable.
b. interval random variable.
c. continuous random variable.
d. parameter.
6.Which of the following statements about histograms is false?
a. The intervals of a histogram do not overlap.
b. Every observation is assigned to one and only one class in a histogram.
c. The intervals of a histogram are equally wide.
d. None of these choices.
7. The relative frequency of a class in a histogram is computed by
a. dividing the frequency of the class by the number of classes.
b. dividing the frequency of the class by the class width.
c. dividing the frequency of the class by the total of all frequencies.
d. None of these choices.
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PRACTICE TEST #1
8. The sum of the relative frequencies for all classes in a histogram always equals
a. the number of classes.
b. the class width.
c. the total of all the frequencies.
d. one.
9. Which of the following is true about a stem-and-leaf display?
a. You can recreate the original data set from it.
b. Its shape resembles a histogram turned on its side.
c. It provides an organized way to depict interval data.
d. All of these choices are true.
10. Which scale of measurement has these two properties: linear distance is meaningful and the
location of origin (or zero point) is arbitrary?
a) Interval level
b) Ordinal level
c) Nominal level
d) Ratio level
e) Minimal level
11. A level of data measurement that has an absolute zero is called _______.
a) interval level
b) ordinal level
c) nominal level
d) ratio level
e) relative level
12. Consider the following frequency distribution:
Class Interval Frequency
10-under 20 15
20-under 30 25
30-under 40 10
What is the relative frequency of the second class?
a) 0.15
b) 0.30
c) 0.10
d) 0.50
e) 0.40
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Document Summary
A company has developed a new computer microprocessor whose average lifetime is unknown. In order to estimate this average, 300 microprocessors are randomly selected from a large production line and tested; their average lifetime is found to be 7 years. The 300 microprocessors represent a: parameter. b. c, population. statistic. sample. 2. a councilman who is running for the office of senator of a state with 3. 5 million registered voters commissions a survey. In the survey, 46% of the 8,000 registered voters interviewed say they plan to vote for him. The population of interest is: a. b. c: all the residents of the state. the 3. 5 million registered voters in the state. the 8,000 registered voters interviewed. the 46% who plan to vote for her. The process of using sample statistics to draw conclusions about population parameters is called: finding the significance level. a: calculating descriptive statistics, doing inferential statistics, calculating the confidence level.
