A university computer lab manager wishes to estimate the mean time that students stay in the lab per visit. She believes that the population standard deviation would be no larger than 10 minutes. Further, she wishes to have a confidence level of 90 percent and a margin of error of ±2.00 minutes. Given this, the sample size that she uses is approximately 60 students.

Question

Quizplus · Accepted Answer

To calculate the sample size, the formula n = (Z*σ/E)^2 is used, where Z is the Z-score for the confidence level, σ is the standard deviation, and E is the margin of error. For a 90% confidence level, Z is approximately 1.645. Plugging in the values (1.645*10/2)^2 gives a sample size of approximately 68, not 60.

A University Computer Lab Manager Wishes to Estimate the Mean