An agricultural researcher wishes to see if a kelp extract helps prevent frost damage on tomato plants. Two similar small plots are planted with the same variety of tomato. Plants in both plots are treated identically, except that the plants on plot 1 are sprayed weekly with a kelp extract, while the plants on plot 2 are not. After the first frost in the autumn, the percentage of damaged fruit is determined. For plants in plot 1, 20 of the 100 tomatoes on the vine exhibited damage. For plants in plot 2, 36 of the 100 tomatoes on the vine showed damage. Let p1 be the actual proportion of all tomatoes of this variety that would experience crop damage under the kelp treatment, and let p2 be the actual proportion of all tomatoes of this variety that would experience crop damage under the no-kelp treatment, assuming that the tomatoes are grown under conditions similar to those in the experiment. A. Construct a 95% confidence interval for p1 p2. B. Is there evidence of a decrease in the proportion of tomatoes suffering frost damage for tomatoes sprayed with kelp extract at significance level a = 0.03