Question

the variable z is directly proportional to x. when x is 15, z has the value of 120. what is the value of z when x=25

Answer 1

The governing equation here is y = kx.

When x is 15, z = 120. Find k:

120 = k(15) leads to k = 120/15, or 8. Then y = 8x.

Now, what iz z when x =25? Substitute 25 for x in y = 8x: y = 200 (answer)