A doctor wants to estimate the mean HDL cholesterol of all 20- to 29-year-old females. How many subjects are needed to estimate the mean HDL cholesterol within

2

points with

99%

confidence assuming

s=12.2

based on earlier studies? Suppose the doctor would be content with

95%

confidence. How does the decrease in confidence affect the sample size required?

LOADING...

Click the icon to view a partial table of critical values.

Question content area bottom

Part 1

A 99% confidence level requires

enter your response here

subjects. (Round up to the nearest subject.)

Part 2

A

95%

confidence level requires

enter your response here

subjects. (Round up to the nearest subject.)

Part 3

How does the decrease in confidence affect the sample size required?

A.

Decreasing the confidence level increases the sample size needed.

B.

Decreasing the confidence level decreases the sample size needed.

C.

The sample size is the same for all levels of confidence.