Question

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

44

points with

99 %99%

confidence assuming

s equals 18.9s=18.9

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

95 %95%

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

​A 99% confidence level requires 149149 subjects. ​(Round up to the nearest​ subject.)

A 95 %95% confidence level requires 8686 subjects. ​(Round up to the nearest​ subject.)

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

A.

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

B.

Decreasing the confidence level decreases the sample size needed.

C.

Decreasing the confidence level increases the sample size needed.

what is the answer.... A,B or C?

Answer 1