Question 20 (1 point) Imagine you are an analyst for local grocery store, and plan to investigate differences between sales promotions in terms of effectiveness at increasing a customer's sales. After sampling 207 people, equally split between each promotion, the following results were gathered: Paper Coupon Digital Coupon Rebate Median 39.22 44.73 30.42 Mean 75.74 55.86 38.92 SD 8.04 9.19 4.20 Using this information, what is the mean square due to error MSE? Give your answer accurate to the nearest integer. Your