A district manager rewards sales teams based on overall sales generated in a month. The data for earnings are shown in the table, where Low represents the lowest sales and High represents the highest sales generated by a single sales team member. Team Low High Range Mean Median IQR σ
Team X 190 2280 2090 1005.9 921.5 841.75 542.7
Team Y 745 1820 1075 1165.5 1147.5 447 262.1
Team Z 950 2275 1325 1906.6 2015.5 362.3 283.6
Part A: If the manager wants to award the sales team that has the most consistent earnings among its team members, which team should it choose and why? Justify your answer mathematically. (5 points)

Part B: If the manager wants to award the sales team with the highest average earnings, which team should it choose and why? Justify your answer mathematically. (5 points)