A local company makes a candy that is supposed to weigh 1.00 ounces.A random sample of 25 pieces of candy produces a mean of 0.996 ounces with a standard deviation of 0.004 ounces.How many pieces of candy must we sample if we want to be 99 percent confident that the sample mean is within 0.001 ounces of the true mean?
A) 126
B) 124
C) 107
D) 12
E) 6

Question

Quizplus · Accepted Answer

The sample size needed to be 99% confident that the sample mean is within 0.001 ounces of the true mean is 126. This is calculated using the formula n = (Z^2 * s^2) / e^2, where Z is the z-score for the desired confidence level, s is the sample standard deviation, and e is the margin of error. In this case, Z = 2.576, s = 0.004, and e = 0.001, so n = (2.576^2 * 0.004^2) / 0.001^2 = 126.

A Local Company Makes a Candy That Is Supposed to Weigh