Determine whether y varies directly with x. If so, find the constant of variation k and write the equation.

If y = 2.52 when x = 8.4, what is y when x = 2.7
A. 9
B. -9
C. 0.81
D. -0.81

1 answer

To determine whether y varies directly with x, we need to check if the ratio of y to x is constant.

Given that y = 2.52 when x = 8.4, we can find the constant of variation, k.

k = y/x = 2.52/8.4 = 0.3

Now, to find y when x = 2.7, we can use the equation y = kx.

y = 0.3 * 2.7 = 0.81

Therefore, the answer is C. 0.81.