Posted by Maureen on .
A computer repair service found that a random sample of 45 repair costs had a mean cost of $659. Assume that the population standard deviation is $125. Calculate the margin of error, E, for a 95% confidence interval for the population mean µ.

Statistics 
PsyDAG,
95% = mean ± 1.96 SEm
SEm = SD/√n
I'll let you do the calculations.