Answer Happy

A simple random sample is chosen from a Normal population with o unknown. What is the distribution of (X – u)/(S/Vn)? Select one: a. N(0, 1) (exact) O b. N(0, 1) (approximate) c. t with n-1 degrees of freedom (exact) d. t with n-1 degrees of freedom (approximate)
A population has mean 10 and variance 18. A random sample of size 100 is chosen. The distribution of the sample mean is ... Select one: a. approximately N(10, 18) b. approximately N(10, 0.18) c. Bin(100, 0.18) d. None of the above
We wish to estimate a population mean to within 0.5 with 95% confidence. From previous data, we have seen that s = 4. What is the required sample size? Select one: a. 95 b. 174 c. 246 d. 57,600