The mean income per person in the United States is $37,500, and the distribution of incomes follows a normal distribution. A random sample of 12 residents of Wilmington, Delaware, had a mean of $46,500 with a standard deviation of $9,000. At the .01 level of significance, is that enough evidence to conclude that residents of Wilmington, Delaware, have more income than the national average?
1-State the decision rule for .01 significance level (3 decimal places)
2-Compute the value of the test statistic (2 decimal places)