Question

Historically, students who take OSCM 5510 have a mean score of 85 and a standard deviation of 8. A random sample of 25 OSCM 5510 students is selected. The expected value and the standard deviation of their average score are

a.	25 and 1.6
b.	85 and 1.6
c.	25 and 8
d.	85 and 8

Answer 1

Solution:- (b) The expected value and the standard deviation of their average score are 85 and 1.60.

The expected value of their average score are 85.

S.D = 8

n = 25

$s _{\bar{x}}=\frac{\sigma }{\sqrt{n}}$

$s _{\bar{x}}=\frac{8}{\sqrt{25}}$

The standard deviation of their average score are 1.60.