In order to compare two fertilizers A and B 12 equally sized

In order to compare two fertilizers A and B, 12 equally sized corn fields are selected. Fertilizer A is randomly assigned to 5 of the 12 fields. Fertilizer B is applied to the remaining 7. We want to know if there is sufficient statistical evidence to conclude that brand B produces more ecorn than Brand A. Calculate using the exact Wilcoxon rank-sum test:

Brand A: N= 5, Mean Rank = 4.00, Sum of Ranks = 20.00

Brand B: N=7, Mean Rank = 8.29, SUm of Ranks = 58.00

(b) Now use the approximate Wilcoxon rank-sum test based on the sum of ranks given below:

Brand A: n=20, Mean Rank = 17.05, Sum of Ranks = 341.00

Brand B: n=20, Mean Rank = 23.95, Sum of Ranks = 479.00

Solution

The sum of ranks for Brand A is 20

The sum of ranks for brand B is 58.

Since the sum of ranks of brand A is small thus the test statistic is 20.

Thus, reject the null hypothesis.