13.6 The data in the following table represent the number of hours of relief provided by five different brands of headache tablets administered to 25 subjects experiencing fevers of 38◦C or more. Perform the analysis of variance and test the hypothesis at the 0.05 level of significance that the mean number of hours of relief provided by the tablets is the same for all five brands.

Discuss the results.

Tablet A B C D E 5.2 9.1 3.2 2.4 7.1 4.7 7.1 5.8 3.4 6.6 8.1 8.2 2.2 4.1 9.3 6.2 6.0 3.1 1.0 4.2 3.0 9.1 7.2 4.0 7.6