b) From Minitab we obtain the following values for mean and standard errors of the mean.
MAJ N MEAN SEMEAN POL 1 18 3.361 0.249 3 22 3.091 0.215 4 23 3.439 0.222 5 5 3.400 0.245 11 36 3.028 0.152
3.5 | + | 3.4 | + | + 3.3 | | 3.2 | | 3.1 | | + 3.0 | + +-----+-----------+-----------+-----------+-----------+--- psych bio pps soc other
c) The average response in the 5 groups seem very similar. the small differences can be attributed to chance. The sample means are so close that it is impossible to tell whether differences reflect true effects, or are just due to random errors.