A comparison of the precisions of two machines developed for extracting juice from oranges is to he made using the following data. Machine A Machine B 52 = 2.6 ounces2 .52 = 1.6 ounces2 n : 31 n = 31 (a) Is there sufcient evidence to indicate that there is a difference in the precision of the two machines at the 5% level of signicance? State the null and alternative hypotheses. 2 2 2 O H0: 512