In order to study the relationship between student'smajor(1 for natural science, 2 for social science, 3 for humanities, 4 for fine arts, 5 for business and 6 for nursing) andGPA(grade point average), a random sample of 50 undergraduate students was taken. The number of observations (n), the sample mean (mean) and the sample standard deviation (sd) of GPA for each major are summarised in the following table:

GPA Major 3 4 5 6 n 8 9 CO 7 10 7 mean 2.92 3.09 2.85 3.05 2.85 2.84 sd 0.58 0.52 0.56 0.53 0.69 0.65