Question

Suppose that, based on a sample, the 95% confidence interval for the mean of a population is (23, 39). What was the mean of the sample?

A. 33
B. 31
C. 35
D. 37

Answer 1

Is this as simple as adding (23+39)/2= 31 or is there more to this question. I know that 95%=2 standard deviations.

Answer 2

@perl

Answer 3

B

Answer 4

the mean of the sample is in the middle of the confidence interval. so you can find the midpoint of that interval:
(23 + 39)/2

Answer 5

oh ok so 31 then