An engineer for an industrial components manufacturer is planning to buy a new machine. The engineer decides that the new machine will be purchased if there is evidence that the parts produced have a higher average breaking strength than those generated from the old machine. A sample of 20 parts taken from the old machine indicates a mean of 65 kilograms and standard deviation is 6.4 kilograms. A sample of 21 parts from the new machine yields a mean of 72 kilograms and a standard deviation of 6.1 kilograms.
i. Based on this sample, should the engineer buy the new machine? Test at 2% significance level. Assume the observations from the two populations are normally distributed and have a common variance of five.