1. A simple random sample of 100 observations was taken from a large population. The sample mean and the standard deviation were determined to be 50 and 20, respectively. The standard error of the mean is

a. 2

b. 5

c. 10

d. 0.5

1.2 If a null hypothesis is rejected in favor of an alternative hypothesis, it is

a. not possible a type 1 error

b. a possible type 2 error

c. possible a type 2 error has occurred

d. possible either a type 1 or a type 2 error has occurred