Test the given claim using the traditional method of hypothesis testing. Assume that the sample has been randomly selected from a population with a normal distribution.
A manufacturer makes ball bearnings that are supposed to have a mean weight of 30g. A retaler suspects that the mean weight is actually less than 30g. The mean weight for a random sample of 16 ball bearings is 28.8g with a standard deviation of 3.8g. At the 0.05 significance level, test the claim that the mean is less than 30g.