1Starting salaries of 110 college graduates who have taken a

1.Starting salaries of 110 college graduates who have taken a statistics course have a mean of $42,676 and a standard deviation of $10,554.
Using 99% confidence, find both of the following:

A.   The margin of error E ?

B. The confidence interval for the mean ?

2.The operations manager of a large production plant would like to estimate the average amount of time workers take to assemble a new electronic component. After observing a number of workers assembling similar devices, she guesses that the standard deviation is 10 minutes. How large a sample of workers should she take if she wishes to estimate the mean assembly time to within 24 seconds. Assume the confidence level to be 97%.

A.Sample Size?

Solution