Question

1.1 In your own words, define and give an example of each of the following statistical terms. a.
population
b. sample statistic
e.
c. parameter d.
statistical inference

1.2 Briefly describe the difference between descriptive statistics and inferential statistics.

1.3 A politician who is running for the office of mayor of a city with 25,000 registered voters commissions a survey. In the survey, 48% of the 200 registered voters interviewed say they plan to vote for her. a.
What is the population of interest? b. What is the sample?
c.Is the value 48% a parameter or a statistic? Explain.

1.4 A manufacturer of computer chips claims that less than 10% of its products are defective. When 1,000 chips were drawn from a large production, 7.5% were found to be defective.

a.What is the population of interest?

b. What is the sample?

c. What is the parameter?
d. What is the statistic?

e.Does the value 10% refer to the parameter or to the statistic?

f. Is the value 7.5% a parameter or a statistic?

g. Explain briefly how the statistic can be used to make inferences about the parameter to test the claim.

1.5 Suppose you believe that, in general, graduates who have majored in your subject are offered higher salaries upon graduating than are graduates of other programs. Describe a statistical experiment that could help test your belief.

1.6 You are shown a coin that its owner says is fair in the sense that it will produce the same number of
heads and tails when flipped a very large number of times.

a.Describe an experiment to test this claim.

b. What is the population in your experiment?

c. What is the sample?

d. What is the parameter?
e. What is the statistic?

f. Describe briefly how statistical inference can be used to test the claim.

1.7 Suppose that in Exercise

1.6 you decide to flip the coin 100 times.

a.What conclusion would you be likely to draw if you observed 95 heads?
b. What conclusion would you be likely to draw if you observed 55 heads?
c.Do you believe that, if you flip a perfectly fair coin 100 times, you will always observe exactly 50 heads? If you answered “no,” then what numbers do you think are possible? If you answered “yes,” how many heads would you observe if you flipped the coin twice? Try flipping a coin twice and repeating this experiment 10 times and report the results.

1.8 Xr01-08 The owner of a large fleet of taxis is trying to estimate his costs for next year’s operations. One major cost is fuel purchase. To estimate fuel purchase, the owner needs to know the total distance his taxis will travel next year, the cost of a gallon of fuel, and the fuel mileage of his taxis. The owner has been provided with the first two figures (distance estimate and cost of a gallon of fuel). However, because of the high cost of gasoline, the owner has recently converted his taxis to operate on propane. He has measured and recorded the propane mileage (in miles per gallon) for 50 taxis.

a.What is the population of interest?
b. What is the parameter the owner needs?

c. What is the sample?
d. What is the statistic?

e. Describe briefly how the statistic will produce the kind of information the owner wants.

Answer 1