Question

Problem 1-3 pertain to the following information. The serum cholesterol levels in men aged 18 to 24 is normally distributed with mean 178.1 and a standard deviation 40.7. 1. If a man age 18 to 24 is randomly selected, the probability that his serum cholesterol level is between 96.7 and 259.8 is about: a. 0.68 b. 0.75 c. 0.95 d. 0.50 e. 0.89 2. If 20 men were randomly selected, the mean and standard deviation of sample mean are a. 178.1, 40.7 b. 178.1, 9.10 C. 178.1, 20.3 d. 178.1, 15 e. 178.1, 25 3. The probability that the average cholesterol levels of these 20 randomly selected workers will is between 96.7 and 259.8 is about a. 85 b. 90 c. 1.00 d. .63 e..79

Answer 1

2) If 20 men were randomly selected lie. n=20 1 Sample mean = x= ? xi We know, X WN(4 0² . Mean of sample mean = 1=178.1 and standard deviation of sample mean is, 40.7 = 40.7 = 9.1008 un - do 4.4721 3) Probability that the average cholesterol levels of zo randomly selected workers will between 96.7 and 259.8 We know, XNN 1 02 : 2 = N N o , x - l olan ..pl 96,7 < x < 259,8) = < P/96.7-178.) C 9.1008 P/- 8.94 << x-l < 259.8-178.). olan 9.1008 < 8.97) = P 2 c -8.94) = = = (Z 1- <8.97) - P 0 1