You proposed a "Premium Shipping To Increase Sales" project to your boss, but this project in signicant shipping expense. Your boss was reluctant to fund this project since your boss thou project might not work. In order to support your proposal, you selected similar product catego comparing a test group with a control group. The test group consisted of 40 SKUs; the rest 40( treated as a control group. Based on the given information in this table, please nd the z-scort of the test group only. Note: Like any other deviation concepts, the Z-score from the ttest might come out negative I please ignore the sign and put only the value as your answer. For example, if your z-score is -3 38.56 as an answer. Test Group (unit in $ 1: 1000)/Month Before After Mean of Sales = $ 115 Mean of Sales = $ 234 With Std Dev = $ 11 With Std Dev = $ 13 Control Group Before After Mean of Sales = $ 105 Mean of Sales = $ 250 With Std Dev = $ 9 With Std DeV = $ 15