A lake in Southern Ontario is classified as small if its area is smaller than 20 hectares (ha), medium for an area between 20 and 100 ha, and large for an area above 100 ha. Given below are the measured alkalinity values (in CaCO3 mg/L) for 12 randomly selected medium lakes and 15 randomly selected large lakes. We are to proceed with a non-parametric test for the equality of alkalinity of the medium and large lakes vs. the two-sided alternative. Calculate the appropriate test statistic for the nonparametric test (base it on the ranks of the medium lakes). Medium: 3 4.5 8 13 18 21.5 22 4 6.5 29 27 28.5

Large: 5 9 14.5 29 4.5 36 26.5 28 30.5 31.5 37 38 6.5 8 39