Question

Homework: 3-2 MyStatLab: Module Three Problem Set Save Score: 0 of 5 pts 14 of 14 (13 complete) HW Score: 70.52%, 45.84 of 65 pts 9.2.41 EQuestion 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 4 points with 99% confidence assuming s 15.5 based on earlier studies? Suppose the doctor would be content with 95% confidence. How does the decrease in confidence affect the sample size required? 昌Click the icon to view a partial table of critical values. A 99% confidence level requires 1100 subjects. (Round up to the nearest subject.) A 95% confidence level requires 11 subjects. (Round up to the nearest subject.) Partial Critical Value Table -X Level of Confidence, Area in Each Tail,Critical Value, z (1-1) . 100% 90% 95% 99% 0.05 0.025 0.005 1.645 1.96 2.575 Print Done Enter your answer in the answer box and then click Check Answer. Clear All remaining

Answer 1

1. n = ((Z_0.005 *Sigma/ E)² = ((2.576*15.5)/4)² = 99.64

                     (Round to the nearest whole number)

                     n = 100

2. n = ((Z_0.025 * Sigma)/E)² = ((1.96*15.5)/4)²   = 57.68

     (Round to the nearest whole number)

      n = 58