Wilcoxon RankSum Test. In Exercises 58, use the Wilcoxon ranksum test.Clinical Trials of Lipitor The sample data below are changes in LDL cholesterol levels in clinical trials of Lipitor (atorvastatin). It was claimed thatLipitor had an effect on LDL cholesterol. (The data are based on results given in a ParkeDavis memo from David G. Orloff, M.D., the medical teamleader for clinical trials of Lipitor. Pfizer declined to provide the author with the original data values.) Negative values represent decreases in LDLcholesterol. Use a 0.05 significance level to test the claim that for those treated with 20 mg of atorvastatin and those treated with 80 mg of atorvastatin,changes in LDL cholesterol have the same median. What do the results suggest?Group treated with 20 mg of atorvastatin : 28 32 29 39 31 35 25 36 35 26 29 34 30 Group treated with 80 mg of atorvastatin : 42 41 38 42 41 41 40 44 32 37 41 37 34 31

Inference for two independent groups: - This means deciding if there’s a statistically significant relationship between explanatory and response variable - If response variable is quantitative, the question involves means o Ex. How does average childhood weight compare between...