Agriculture: Bell Peppers The pathogen Phytophthora capsici causes bell peppers to wilt and die. Because bell peppers are an important commercial crop, this disease has undergone a great deal of agricultural research. It is thought that too much water aids the spread of the pathogen. Two fields are under study. The first step in the research project is to compare the mean soil water content for the two fields (Source: Journal of Agricultural, Biological, and Environmental Statistics, Vol. 2, No. 2). Units are percent water by volume of soil.

Field A samples, x1:

10.2 10.7 15.5 10.4 9.9 10.0 16.6 15.1 15.2 13.8 14.1 11.4 11.5 11.0 Field B samples, x2:

8.1 8.5 8.4 7.3 8.0 7.1 13.9 12.2 13.4 11.3 12.6 12.6 12.7 12.4 11.3 12.5

(i) Use a calculator with mean and standard deviation keys to verify that x1 < 12.53, s1 < 2.39, x2 < 10.77, and s2 5 2.40.

(ii) Assuming the distribution of soil water content in each field is mound-shaped and symmetric, use a 5%

level of significance to test the claim that field A has, on average, a higher soil water content than field B.

AppendixLO1