Direct variation

Let y = k√x
a) if x is increasde by 10% :
k√(1.1x) = (√1.1) k√x = (√1.1)y = 1.0488y
i.e. y increased 4.88%(3 sig.fig)
b) if x is decreased by 5% :
k√(0.95x) = (√0.95) k√x = (√0.95) y =0.9747y
i.e. y decreased 1 - 0.9747 = 0.0253 = 2.53%(3 sig.fig)