Explore BrainMass

Finding appropriate sample mean

In order to set rates, an insurance company is trying to estimate the number of sick days that full time workers at an auto repair shop take per year. A previous study indicated that the population standard deviation was 2.1 days.

How do I find a sample large enough for the company that wants to be 92% confident that the true mean differs from the sample mean by no more than 1/2 day?

How would I find the sample size necessary using a 96% confidence interval?

Solution Summary

This solution finds the sample mean corresponding to two given confidence intervals.