The Net Weights (In Grams)of a Sample of Bottles Filled

Multiple Choice

The net weights (in grams) of a sample of bottles filled by a machine manufactured by Edne,and the net weights of a sample filled by a similar machine manufactured by Orno,Inc.,are shown here. Testing the claim at the 0.05 level that the mean weight of the bottles filled by the Orno machine is greater than the mean weight of the bottles filled by the Edne machine,what is the critical value? Assume equal standard deviations for both samples.

A) +2.179
B) +2.145
C) +1.782
D) +1.761