CHAPTER 1 SECTION 1: WHAT IS STATISTICS?
MULTIPLE CHOICE
1. You take a random sample of 100 students at your university and find that their
average GPA is 3.1. If you use this information to help you estimate the average GPA for all
students at your university, then you are doing what branch of statistics?
a. Descriptive statistics
b. Inferential statistics
c. Sample statistics
d. Population statistics
ANS: B PTS: 1 REF: SECTION 1.1
2. A company has developed a new computer sound card whose average lifetime is
unknown. In order to estimate this average, 200 sound cards are randomly selected from a large
production line and tested; their average lifetime is found to be 5 years. The 200 sound cards
represent a:
a. parameter.
b. statistic.
c. sample.
d. population.
ANS: C PTS: 1 REF: SECTION 1.1
3. A company has developed a new computer sound card whose average lifetime is
unknown. In order to estimate this average, 200 sound cards are randomly selected from a large
production line and tested; their average lifetime is found to be 5 years. The 5 years represents a:
a. parameter.
b. statistic.
c. sample.
d. population.
ANS: B PTS: 1 REF: SECTION 1.1
4. A descriptive measure that is computed from a sample is called a:
a. parameter.
b. statistic.
c. population.
d. sample.
ANS: B PTS: 1 REF: SECTION 1.1
5. A summary measure that is computed from a population is called a:
a. sample.
b. statistic.
c. population.
d. parameter.
ANS: D PTS: 1 REF: SECTION 1.1
6. Which of the following is a measure of the reliability of a statistical inference?
a. A population parameter.
b. A significance level.
c. A descriptive statistic.
d. A sample statistic.
ANS: B PTS: 1 REF: SECTION 1.1
7. A politician who is running for the office of governor of a state with 4 million
registered voters commissions a survey. In the survey, 54% of the 5,000 registered voters
interviewed say they plan to vote for her. The population of interest is:
a. the 4 million registered voters in the state.
b. the 5,000 registered voters interviewed.
c. the 54% who plan to vote for her.
d. all the residents of the state.
ANS: A PTS: 1 REF: SECTION 1.1
8. A company has developed a new battery and wants to estimate its average
lifetime. A random sample of 500 batteries is tested and the average lifetime of this sample is
found to be 225 hours. The 225 hours is the value of a:
a. parameter.
b. statistic.
c. sample.
d. population.
ANS: B PTS: 1 REF: SECTION 1.1
9. 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.
ANS: C PTS: 1 REF: SECTION 1.1
10. Which of the following represents a population, as opposed to a sample?
a. 1,000 respondents to a magazine survey
which has 500,000 subscribers.
b. The first 10 students in your class completing
a final exam.
c. Every fifth student to arrive at the book store
on your campus.
d. All registered voters in the State of Michigan.
ANS: D PTS: 1 REF: SECTION 1.1
11. A researcher at Michigan State University (MSU) wants to estimate the average
number of credits earned by students last semester at MSU. She randomly selects 500 students
from last semester and finds that they averaged 14.85 credits per student. The population of
interest to the researcher is:
a. all MSU students.
b. all college students.
c. all MSU students enrolled last semester.
d. the 500 MSU students selected at random.
a. all MSU students.
b. all college students.
c. all MSU students enrolled last semester.
d. the 500 MSU students selected at random.
ANS: C PTS: 1 REF: SECTION 1.1
12. A study is under way to determine the average height of all 32,000 adult pine
trees in a certain national forest. The heights of 500 randomly selected adult pine trees are
measured and analyzed. The sample in this study is:
a. the average height of the 500 randomly
selected adult pine trees.
b. the average height of all the adult pine trees in
this forest.
c. all the adult pine trees in this forest.
d. the 500 adult pine trees selected at random
from this forest.
ANS: D PTS: 1 REF: SECTION 1.1
13. A study is under way to determine the average height of all 32,000 adult pine
trees in a certain national forest. The heights of 500 randomly selected adult pine trees are
measured and analyzed. The parameter in the study is:
a. the average height of the 500 randomly
selected adult pine trees.
b. the average height of all the adult pine trees in
this forest.