A well-known conglomerate claims that its detergent whitens and brightens better than all the rest. In order

A well-known conglomerate claims that its detergent “whitens and brightens better than all the rest.” In order to compare the cleansing action of the top three brands of detergents, 24 swatches of white cloth were soiled with red wine and grass stains and then washed in front-loading machines with the respective detergents. The following whiteness readings were obtained:

a. Construct an ANOVA table. Assume whiteness readings are normally distributed.

b. Specify the competing hypotheses to test whether there are some differences in the average whitening effectiveness of the three detergents.

c. At the 5% significance level, what is the conclusion to the test?

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Detergent 2 78 74 81 86 86 89 69 79 3 87 80 91 84 79 87 85 94 89 89 83 78 8 79 78 X1 = 86.3 s-20.8 ぬ= 80.3 = 45.1 x= 82.5 80.9 2 så = 27.3