Question: Manufacturing and Product Development Shelf Safe Milk does not need to be refrigerated until it is opened. Although it is convenient, there is some concern that this Grade A milk contains less protein than regular milk. Independent random samples of 8-ounce servings of Shelf Safe Milk and regular milk were obtained, and the amount of protein (in grams) in each was measured. The summary statistics are given in the following table.
Is there any evidence to suggest that the population mean amount of protein in Shelf Safe Milk is less than the population mean amount of protein in regular milk? Use a = 0.01, and assume the underlying distributions are normal, with equal variances.