The stem-and-leaf plot shows the heights in centimeters of teddy bear sunflowers grown in two different types of soil. soil a soil b 5 9 5 2 1 1 6 3 9 5 1 0 7 0 2 3 6 7 8 2 1 8 3 0 9 key: 9 6 means 69 key: 5 8 means 58 a.)calculate the mean of each data set. b.)calculate the mean absolute deviation (mad) of each data set. c.)which set is more variable? how do you know?