Question

X is directly proportional to y. When x is 4 then y is 10. Find y when x is 15.

Answer 1

Explanation:

The term directly proportional means that

`x = ky`

Where k is the constant of variation

Solving for k,

`4 = k(10)`

`k = 0.4`

So

`15 = 0.4(y)`

`(15)/(0.4) = y`

`y = 37.5`