In a class of 30 students. everyone has either a pierced nose or a pierced ear. the professor asks everyone with a pierced nose to raise his or her hand. eight hands go up. then the professor asked everyone with a pierced ear to do likewise. this time there are 24 hands raised. how many students have piercings both on their ears and their noses?

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 calculate the mean of each data set. calculate the mean absolute deviation (mad) of each data set. which set is more variable? how do you know?