1. A local realtor wants to determine the average value for single-family houses in a community.A random sample of 50 houses is selected. The sample mean value is found to be $220,000 with a sample standard deviation of $40,000.

a) Assuming that the values of all single-family houses in the community is normally distributed, compute a 90% confidence interval estimate for #, where / is the population mean value for all single-family houses in the community. b) Test the hypothesis Ho: # =240,000 versus Ha: #