Two Population Means
At a recent faculty meeting, we were wondering if freshmen have more free time than seniors. We took a sample of 25 freshmen and 23 seniors. Each student was asked to record the amount of free time he or she had in a typical week. The mean for the freshmen was found to be 29 hours of free time per week with a standard deviation of 7.0 hours. For the seniors, the mean was 22 hours of free time per week with a standard deviation of 6.2 hours. Assume that the two populations are normally distributed with equal but unknown population standard deviations. Test at a 5% significance level whether the two-population means are different.
|If This Problem Calls for:||Use Test Statistic||Use Degrees of Freedom|
|Pooled Variance Test||3.897||Calculate your own|
|Separate Variance Test||3.655||46|
|Paired Samples Test||2.546||Calculate your own|
|Chi-squared Test||Calculate your own||Calculate your own|