In the mid-1970s, a study on the prices of various motor oils was conducted in (what passes for) a large town in Montana.

The study consisted of pricing four brands of oil at each of nine stores. The data are given below.

Brand Store P H V Q 1 87 95 95 82 2 96 104 106 97 3 75 87 81 70 4 81 94 91 77 5 70 85 87 65 6 85 98 97 83 7 110 123 128 112 8 83 98 95 78 9 105 120 119 98 Analyze these data.