Bags of Pretzels Are Sampled to Ensure Proper Weight

Multiple Choice

Bags of pretzels are sampled to ensure proper weight.The overall average for the samples is 9 ounces.Each sample contains 25 bags.The standard deviation is estimated to be 3 ounces.The upper control chart limit (for 99.7% confidence) for the average would be ________ ounces.

A) 9.4
B) 18.0
C) 10.2
D) 10.8