Backfat thickness is a variable used in evaluating the meat quality of pigs. An animal scientist measured backfat thickness (cm) in pigs raised on two different diets, with the results given in the table.
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Diet 1
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Diet 2
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Mean
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3.49
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3.05
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Standard Deviation
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0.4
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0.4
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Consider using the test to compare the diets. Bracket the p-value, assuming that the number of pigs on each diet was (a) 5 (b) 10 (c) 15. Use n1 + n2 - 2 as the approximate degrees of freedom.