Question

9.2.41 Question Help 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 3 points with 99% confidence assuming s-11.9 based on earlier studies? Suppose the doctor would be content with 95% confidence. How does the decrease in confidence affect the sample size required? Click the icon to view a partial table of critical values A 99% confidence level requires subjects (Round up to the nearest subject.) Partial Critical Value Table Level of Confidence,Area in Each Tail, a Critical Value, za/2 (1-a)* 100% 90% 95% 99% 0.05 1.645 1.96 575 0.005 Print Done Enter your answer in the answer box and then click Check Answer parts remaining Clear All Check Answer

Answer 1