Chapter 19, Problem 8E

(a)

To determine

To explain which statement is true.

Answer to Problem 8E

True.

Explanation of Solution

It is given that several factors are involved in the creation of a confidence interval. Among the mare the sample size, the level of confidence and the margin of error. Thus, we have that for a given sample size reducing the margin of error will mean lower confidence. This statement is true because of the relationship between margin of error and confidence level and margin of error and sample size.

(b)

To determine

To explain which statement is true.

Answer to Problem 8E

True.

Explanation of Solution

It is given that several factors are involved in the creation of a confidence interval. Among the mare the sample size, the level of confidence and the margin of error. Thus, we have that for a certain confidence level, you can get a smaller margin of error by selecting a bigger sample. This statement is true because of the relationship between margin of error and confidence level and margin of error and sample size.

(c)

To determine

To explain which statement is true.

Answer to Problem 8E

True.

Explanation of Solution

It is given that several factors are involved in the creation of a confidence interval. Among the mare the sample size, the level of confidence and the margin of error. Thus, we have that for a fixed margin of error, smaller samples will mean lower confidence. This statement is true because of the relationship between margin of error and confidence level and margin of error and sample size.

(d)

To determine

To explain which statement is true.

Answer to Problem 8E

True.

Explanation of Solution

It is given that several factors are involved in the creation of a confidence interval. Among the mare the sample size, the level of confidence and the margin of error. Thus, we have that for a given confidence level a sample nine times as large will make a margin of error one third as big. This statement is true because of the relationship between margin of error and confidence level and margin of error and sample size.