Qu estion 4: Suppose you wish to determine whether there are differences in the average prices among 3 major supermarkets in Melbourne. You randomly select 8 regularly bought items, each distinct item of the same brand, and observe their unit prices at each supermarket. The following data were obtained: Supermarket A B C Item 1 2.84 2.90 2.82 2 0.51 0.56 0.51 3 1.08 1.10 1.08 4 3.75 3.80 3.70 5 0.77 0.75 0.77 6 1.59 1.54 1.63 7 0.82 0.77 0.77 8 0.65 0.68 0.59 a) Is there a need to block the items? Why? b) What other aspects could be considered that may influence the prices that are being recorded? c) Visually represent the collected data. Are there any visible differences for the average prices for the 3 supermarkets? cl) Use the analysis of variance procedure to test the null hypothesis of no treatment effects. 6) Based on your answer on cl) should you use a multiple comparison method (Le. LSD) here? Explain