Question

If y varies directly with x and y is 37.4 when x is 17, what is the value of x when y is 13.2?

Answer 1

6

Explanation:

We have y ∝ x which is another way of saying y varies directly with x

We can rewrite the direct proportion relation y ∝ x as y = k.x where k is a constant - the constant of proportionality

So y = kx or x = y/k

using y and x values know, we can solve for k and then solve for any x given y

We have

y = 37.4 = k (17)

Therefore k = (37.4/17) = 2.2

To find x given y = 13.2, use the second equation
x = y/k = 13.2 / 2.2 = 6