two machines are supposed to be producing steel bars of approximately the same length. a sample of 25 bars from one machine has an average length of 38 inches with a standard deviation of 0.95 inches. for 28 bars produced by the other machine the corresponding figures are 36 inches and 0.32 inches.

A) using the 0.02 level of significance, test the null hypothesis that the population means are equal

B) construct and interpret the 98% confidence interval for the difference between the population means