A sample of 40 sales receipts from a grocery store has x = $137 and s = $30.2. Assist the owner of the grocery store to these values to test, at the 5% level of significance, whether or not the mean sales at the grocery store is different from $150.
(a) State the null and alternative hypotheses for the test.
(b) Calculate the test statistics.
(c) Determine the rejection region(s) for the test.
(d) State the conclusion for the test giving reasons for your answer.