In a completely randomized experimental design, three brands of paper towels were tested for their ability to absorb water. Equal-size towels were used, with four sections of towels tested per brand. The absorbency rating data follow. At a .05 level of significance, does there appear to be a difference in the ability of the brands to absorb water?

Brand

x 91, 100, 88, 89

y 99, 96, 94, 99

z 83, 88, 89, 76

Find the variance for each.