Is abc similar to def

This stem-and-leaf plot represents the heights of the students on ralph's basketball team. one student's height is missing from the plot. if the mean height of all the students on the team is 61 inches, what is the missing height? a. 55 in. b. 59 in. c. 61 in. d. 65 in.

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?

Asap! i'm not good math and i'm lost.