A manufacturer makes ball bearings that are supposed to have a mean weight of 30 g. A retailer suspects that the mean weight is actually less than 30 g. The mean weight for a random sample of 16 ball bearings is 29.5 g. with a standard deviation of 4.3 g. At the 0.05 significance level, test the claim that the mean is less than 30 g.
Give the null and alternate hypotheses. also the critical value, the test statistic and the evidence shows or does not show support.