Answer to Question #208015 in Statistics and Probability for Cam

Question

Three sections of the same secondary mathematics course are taught by 3 teachers. The

final grades were recorded as follows:

Teacher X: 77 36 93 45 60 66 73 80 43 82 89 73

Teacher Y: 88 78 48 91 51 85 74 77 31 78 62 76 96 80 56

Teacher Z: 68 79 56 91 71 71 87 41 59 68 53 79 15

Is there a significant difference in the average grades given by the 3 teachers? Use a 0.05

level of significance.