=+32. Change in sales. Suppose the specialty food chain from Exercise 26 wants to now compare the change in sales across different regions. An examination of the difference in sales over a 37-week period in a recent year for 8 stores in the state of Massachusetts compared to 12 stores in nearby states reveals the following descriptive statistics for relative increase in sales. (If these means are multiplied by 100, they show % increase in sales.)

State N Mean StDev MA 8 0.0738 0.0666 Other 12 0.0559 0.0503