Construct a

90%

confidence interval for the population mean,

. Assume the population has a normal distribution. A sample of

15

randomly selected students has a grade point average of

2.29

with a standard deviation of

0.85

.

A. 1.48,3.88

B. 1.90,2.68

C. 2.58, 2.78

D. 2,18, 3.18