Hello,

A random survey of 225 of the 2700 institutions of higher learning in the United States was conducted

in 1976 by the Carnegie Commission. The survey showed a mean enrollment of 3700 students per

institution, and a standard deviation of 6000 students. Construct a 95% confidence interval for the

total student enrollment in all 2700 institutions.

I know the answer is 9990000 +- 2120000 but I'm having trouble coming to this answer.

I know by taking the mean enrollment and multiplying it by the total number of institutions you get the 9990000 but I'm having trouble finding the proper interval.

Sorry about posting in the university math section, if it needs to be moved to the regular statistics thread then please do so.