3. The bioactivity of four different drugs for treating a particular illness was compared in a study. The treatment averages are as follows: y1. = 66.10, y2. = 65.75, y3. = 62.63 , y4. = 63.85. The sample size within each group was n = 7. A partial ANOVA table is provided below: Source SS df MS F Drug 56.10 Error 62.12 Total (a) From the ANOVA table, find the value of the F test statistic. Is this significant evidence that the population mean bioactivity levels are different among the four drugs. (b) We wish to make all pairwise comparisons between the four treatments. How many possible pairwise comparisons are there? (c) Without adjustment for multiplicity, what would the critical value be for an individual pairwise comparison? Use a = .05. (d) If the desired FWER is 0.05, what would Tukey's critical value be in this situation? Also, find Bonferroni's and Scheffe's critical values. (e) Using each of the three approaches in (d) above, which pairs of means are significantly different? Hint: Since the sample sizes are equal, you don't have to compute the test statistic every time. (f) Comment on any differences in the results in parts (c), (d) and (e). Which is the most appropriate procedure in this case