Chapter 9.3, Problem 9.60E

a)

To determine

To explain details of the study that Raul could realistically perform to investigate the claim.

Answer to Problem 9.60E

I think it is impossible.

Explanation of Solution

Given:

The claim: “We cover 80% of U.S. adults”

To perform a statistical test, we can randomly select a group of 1000 U.S. adults. We can determine whether these 1000 U.S. adults are listed in the white pages site. If we thoroughly look at topic, then we can see it is impossible to get the decent results. As the selected random sample may not be representative of U.S. adults. Therefore, of selected random sample are spread in the different area of U.S. then it could be costly to reach to them for investigation. Hence, I think it is not possible to access the list of all U.S. adults.

b)

To determine

To explain whether the conclusion will be wrong if he uses significance test.

Answer to Problem 9.60E

Yes

Explanation of Solution

Given:

The claim: “We cover 80% of U.S. adults”

There will be possibility to draw a wrong result using significance test. As statistics, could not provide correct results unless the data collected from population which would be representative of population. Hence, using this we can determine how likely the claim is wrong rather than complete surety.

c)

To determine

To explain whether the conclusion will be wrong if he uses confidence interval.

Answer to Problem 9.60E

Yes

Explanation of Solution

Given:

The claim: “We cover 80% of U.S. adults”

There will be possibility to draw a wrong result using confidence interval. As statistics, could not provide correct results unless the data collected from population which would be representative of population. Hence, using this we can determine how likely the claim is wrong rather than complete surety.