Assuming a population standard deviation of 3 hours, what is the required sample size if the error should be less than ½ hour with a 99% level of confidence?
A) 196
B) 240
C) 15
D) 16

Question

Quizplus · Accepted Answer

We can use the formula n = (zα/2 * σ / E)^2, where zα/2 is the z-score corresponding to the level of confidence, σ is the population standard deviation, and E is the maximum allowable error. Plugging in the given values, we get:
n = (2.576 * 3 / 0.5)^2 = 239.8
Rounding up to the nearest integer, we need a sample size of n = 240.

Assuming a Population Standard Deviation of 3 Hours, What Is