A doctor wants to estimate the mean HDL of all 20-29 year old females. How many subjects are needed to estimate the mean HDL cholesterol with 4 points with 99% confidence assuming s= 11.8 based on earlier studies. Then suppose the doctor would be content with 90% confidence. How does the decrease in confidence affect the sample size required. ( I know the decrease in confidence will decrease sample size)

arest subject.) i Partial Critical Value Table X Level of Confidence, a Critical Value, Za / 2 (1 - () . 100% Area in Each Tail, N| 8 90% 0.05 1.645 95% 0.025 1.96 99% 0.005 2.575 Print Done