In an experiment to compare the quality of four different brands of magnetic recording tape, five 2400-ft reels of each brand (A–D) were selected and the number of flaws in each reel was determined.

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a. What assumptions must be made about the four total polyunsaturated fat distributions before carrying out a single-factor ANOVA to decide whether there are any differences in true average fat content?

b. Carry out the test suggested in part (a). What can be said about the P-value?