How do I do this? 20 points for whoever answers

The variable z is directly proportional to x, and inversely proportional to y. when x is 4 and y is 13, z has the value 1.2307692307692. what is the value of z when x= 9, and y= 20

Kathleen's gross annual salary is $56,820. what is the maximum amount of rent she can afford to pay? round your answer to the nearest dollar. question 1 options: $1146 $1326 $1656 $2368

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.