3. To compare the effectiveness of three different pesticides for controlling pests, a random sampling of 21 plots were carried out. The number of insects' eggs for each plot was recorded and presented in the table below. Pesticide A Pesticide B Pesticide C 80 80 67 65 93 85 73 72 84 71 91 86 63 89 71 64 87 78 78 86a. Use the Kruskal-Wallis test to see if there is a difference in the efficiency of the three pesticides at a 5% significance level. [10 Marks] b. If the null hypothesis is rejected, conduct a post hoc test using Bonferroni procedure at a 10% significance level. [10 Marks] 4. A researcher is interested to know students' preference towards five language courses offered in a public university. Eight students were randomly selected, and they were asked to rate the courses using a scale of 0 (not interested all) to 10 (very interested), in which results from the ratings do not allow us to assume that the data are normally distributed for each course. The ratings given are shown in the table below. Course Student Malay English Arabic Chinese Japanese A 0 - -10 0 + D -1 0 0 0 - E a. At a = 0.05, test the hypothesis that the students have no specific preference for the language course offered using Friedman test. [10 marks] b. If the null hypothesis is rejected, conduct a post hoc test using Bonferroni procedure at a 10% significance level. [10 marks]