Question

(1 point) Starting salaries of 135 college graduates who have taken a statistics course have a mean of $42,583. The population standard deviation is known to be $9,171. Using 99% confidence, find both of the following:

A. The margin of error:

B. Confidence interval: ,

Answer 1

Sample Size (n) =	135
Population Standard Deviation (SD) =	9171
Mean =	42583

Ans A

Z score for 99% confidence =	2.58
Margin of Error = (2.58 * 9171)/(135)^(1/2) =	2036.43

Ans B

Confidence Interval = Mean +/- (margin of Error)
Lower End of the Interval = Mean - (margin of Error) =	40546.57
Upper End of the Interval = Mean + (margin of Error) =	44619.43