One of the factors that determines the degree of risk a pesticide poses to human health is the rate at which the pesticide is absorbed into skin after contact. An important question is whether the amount in the skin continues to increase with the length of the contact, or whether it increases for only a short time before leveling off. To investigate this, measured amounts of a certain pesticide were applied to 20 samples of rat skin. Four skins were analyzed at each of the time intervals 1, 2, 4, 10, and 24 hours. The amounts of the chemical (in micrograms) that were in the skin are given in the following table.

a. Construct an ANOVA table.

b. Can you conclude that the amount in the skin varies with time? Use the α = 0.05 level of significance.

Transcribed Image Text:

Duration Amounts Absorbed 1 1.7 1.5 1.2 1.5 2 1.7 1.6 1.9 1.9 4 1.9 1.7 2.1 2.0 10 2.2 1.9 1.7 1.6 24 2.1 2.2 2.5 2.3