Problem: if x and y are proportional y=2 when x=3 what is the value of y when x=9
if x and y are proportional and y=2 when x=3, what is the value of y when x=9
This simply requires multiplying both values by the same number.
Changing x from 3 to 9 means multiplying by 3.
y * 3 = 2 * 3 = 6
y/x = 2/3
6/9 = 2/3
Answer: y = 6