University administrators wish to estimate the mean time to graduation, for the population of students who actually graduate, to within ± 3 months (one-quarter). It is known that the maximum time to graduation is eight years (96 months) and the minimum time is three years (36 months), so that a conservative estimate of the standard deviation of graduation times is range/4 = (96 − 36)/4 = 15 months. Use this standard deviation estimate to determine the sample size required to achieve the administrators’ goal with 95% confidence.