Question

14) You wish to compare the average GPA of students from one department to another. It is assumed that the distributions of GPA in both departments are normally distributed and that the overall standard deviation of GPA is the same in both departments. If you sample 17 students from the first department and 25 students from the second department, what is the correct (Z or t) multiplier for a 95% Confidence Interval on the mean difference between the 2 departments?