The sample size needed to estimate a population mean within 2 units with a 95% confidence when the population standard deviation equals 8 is
A)62
B)61
C)8
D)None of these choices.

Question

Quizplus · Accepted Answer

The sample size needed to estimate a population mean within 2 units with a 95% confidence when the population standard deviation equals 8 is 62. This is because the sample size 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 population standard deviation, and e is the margin of error. In this case, the z-score for a 95% confidence level is 1.96, the population standard deviation is 8, and the margin of error is 2. Plugging these values into the formula, we get n = (1.96^2 * 8^2) / 2^2 = 61.96. Rounding up to the nearest whole number, we get a sample size of 62.

The Sample Size Needed to Estimate a Population Mean Within