The pulse rate for 20 wrestlers was recorded before and after their wrestling match. The pulse rates are listed in the table.

Pulse before Exercise

67, 67, 67, 68, 71, 72, 72, 75, 77, 77, 79, 81, 85, 87, 87, 91, 97, 98, 103, 111

Pulse after Exercise

87, 88, 89, 89, 91, 93, 93, 95, 96, 97, 98, 98, 101, 105, 105, 119, 125, 122, 125, 149

Part A: On your own paper, create a back-to-back stemplot. Submit a list of the stems you used in order from least to greatest. Justify your reasoning for split or nonsplit stems.

Part B: Compare and contrast the two data sets. Justify your answer using key features of the data.