TABLE 12-18 Two New Different Models of Compact SUVs Have Just Arrived

Short Answer

TABLE 12-18
Two new different models of compact SUVs have just arrived at the market. You are interested in comparing the gas mileage performance of both models to see if they are the same. A partial computer output for twelve compact SUVs of model 1 and thirteen of model 2 is given below:

You are told that the gas mileage population distributions for both models are not normally distributed.
-Referring to Table 12-18, what is the standard deviation of the Wilcoxon rank sum test statistic T₁?