A sample of 30 year fixed mortgage rates at 16 randomly selected banks yields a mean rate of 7.05% and a sample standard deviation of 0.22%. A sample of 30 year fixed mortgage rates at 12 randomly chosen credit unions yields a mean rate of 6.65% and a sample standard deviation of 0.39%. We are curious about whether the mean rates are different between banks and credit unions? Create a 95% confidence interval to estimate the difference of the mean rates between banks and credit unions (DF=16).