The Exchange Bank wishes to determine the mean balance on mortgages it holds. A sample of 36 mortgages showed the mean balance to be $86,000 with a sample standard deviation of $12,000. Would it be...

The Exchange Bank wishes to determine the mean balance on mortgages it holds.  A sample of 36 mortgages showed the mean balance to be $86,000 with a sample standard deviation of $12,000.  Would it be reasonable to conclude that the population mean is less than $90,000?  Use the .05 significance level.