A researcher believes that the percentage of people who exercise in California is greater than the national exercise rate. The national rate is 20%. The researcher gathers a random sample of 120 individuals who live in California and ﬁnds that the number who exercise regularly is 31 out of 120.(a) What is the test statistic?(b) What is df for this test?(c) What is the critical value?(d) What conclusion should be drawn from these results?