15.14 Improved methods for teaching reading. Do new “directed reading activities” improve the reading ability of elementary school students, as measured by their Degree of Reading Power (DRP)

score? A study assigns students at random to either the new method (treatment group, 21 students) or traditional teaching methods (control group, 23 students). Here are the DRP scores at the end of the study:9 Treatment group Control group 24 61 59 46 42 33 46 37 43 44 52 43 43 41 10 42 58 67 62 57 55 19 17 55 71 49 54 26 54 60 28 43 53 57 62 20 53 48 49 56 33 37 85 42 For these data the two-sample t test (Example 7.14) gives P = 0.013 and a permutation test based on the difference of means (Example 16.12) gives P = 0.015. Both of these tests are based on the difference of sample means. Does the Wilcoxon test, based on rank sums rather than means, give a similar P-value?