If y varies directly with the square of x and y = 4.3 when x = 5, what is the value of y when x = 6?

A) 0.2

B) 3.0

C) 5.2

D) 6.2

E) 209.3

Direct variation (aka direct proportionality) means that the ratio of the two variables will always be the same. In this case, .

Once you have that set up, you can solve fairly simply by plugging in the values you’re given:

Round it and you land on D.