Answer:
Step-by-step explanation:
y ∝ x^2
Introducing the proportionality constant, we have
y = kx^2
Given : y= 18 when x = 3
substitute the given values in order to get the constant
i.e 18 = k x 3^2
18 = 9k
k = 2
therefore the formula connecting x and y
⇒ y = 2x^2
To find y if x is 4, just substitute x = 4 into the formula connecting x and y
i.e y = 2 x 4^2
= 2 x 16
= 32
