Given that y and x are directly proportional and y=2 when x=7, find the value of y when x=17.5.

Question

Given that y and x are directly proportional and

y=2 when x=7, find the value of y when x=17.5.

Answer 1

if y = kx where k is the proportionality constant

we find that k = y/x = 2/7

Then y = (2/7)17.5 = 5