Statistics

Statistics Solutions

Many people believe that the average number of Facebook friends is 130. The population standard deviation is 38.2. A random sample of 50 high school students in a particular county revealed that the average number of Facebook friends was 162. At a 0.05, is there sufficient evidence to conclude that the mean number of friends is lesser than 130?
(A)z - test, right tailed
(B)t-test, right tailed
(C)t-test, left tailed
(D)z - test, left tailed