Many college graduates who are employed full-time have longer than 40-hour work weeks. Suppose that we wish to estimate the meannumber of hours, μ, worked per week by college graduates employed full-time. We’ll choose a random sampleof college graduates employed full-time and use the mean of this sample to estimate μ. Assuming that the standard deviationof the number of hours worked by college graduates is 6.10 hours per week, what is the minimum sample size needed in order for us to be 99% confident that our estimate is within 1.4 hours per week of μ?
Carry your intermediate computations to at least three decimal places. Write your answer as a whole number (and make sure that it is the minimum whole number that satisfies the requirements).
This solution calculates the minimum sample size to have a 99% confidence.