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

Question

Quizplus · Accepted Answer

The upper control limit for the average is calculated using the formula: UCL = mean + (Z * (standard deviation/sqrt(n))). For 99.7% confidence, Z is approximately 3. Therefore, UCL = 9 + (3 * (3/sqrt(25))) = 10.8 ounces.

Bags of Pretzels Are Sampled to Ensure Proper Weight