A production process that fills 12-ounce cereal boxes is known to have a population standard deviation of 0.009 ounce. If a consumer protection agency would like to estimate the mean fill, in ounces, for 12-ounce cereal boxes with a confidence level of 92% and a margin of error of 0.001, what size sample must be used?
A) 249
B) 351
C) 512
D) 211

Question

Quizplus · Accepted Answer

The sample size needed is 249. The formula for the sample size is: n = (Z^2 * s^2) / E^2, where Z is the z-score for the desired confidence level, s is the population standard deviation, and E is the margin of error. Plugging in the given values, we get: n = (1.96^2 * 0.009^2) / 0.001^2 = 249.

A Production Process That Fills 12-Ounce Cereal Boxes Is Known