a doctor wants to estimate the mean hdl cholesterol of all 20-29 year old female
ID: 3277530 • Letter: A
Question
a doctor wants to estimate the mean hdl cholesterol of all 20-29 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 90% confidence. how does the decrease in confidence affect the sample size requir a doctor wants to estimate the mean hdl cholesterol of all 20-29 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 90% confidence. how does the decrease in confidence affect the sample size requir a doctor wants to estimate the mean hdl cholesterol of all 20-29 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 90% confidence. how does the decrease in confidence affect the sample size requirExplanation / Answer
here margin of error E=3
for 99% ; z score =2.5758
std deviation =11.9
here sample size n=(z*std deviation/E)2 =~105.
for 90% CI ; z score =1.645
here sample size n=(z*std deviation/E)2 =~43
therefore for 90% confidence interval requirement of sample size reduces.