The variable z is directly proportional to x, and inversely proportional to y. When x is 8 and y is 18, z has the value 1.3333333333333. What is the value of z when x= 13, and y= 22

Answer 1

z = kx/y

4/3 = 8k/18

4/3 = 4k/9

So, k = 3

z = 3x / y

When x = 13 and y = 22, z = 3(13)/22 = 39/22