Five years ago the average household income in a certain region was $19,857. An economist studying economic growth wishes to test, at the 10% level of significance, whether it has increased now. In a random sample of 50 households the economist calculates, the average income to be $20,058 with a sample standard deviation of $1,143. a. Perform the test using the information collected by the economist using the critical value approach. b. Use the p-value approach and compare the results with the results obtained using the critical value approach.