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
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.
To determine whether y varies directly with x, we need to check if there is a constant of variation that relates the two variables.
Let's calculate the constant of variation, k:
k = y / x
To find k, we can use the values given:
k = 2.52 / 8.4
k ≈ 0.3
Since k is a constant value, we can conclude that y varies directly with x.
Now, to find the value of y when x = 2.7, we can use the equation:
y = k * x
Substituting the values we have:
y = 0.3 * 2.7
y = 0.81
Therefore, the value of y when x = 2.7 is 0.81.
The correct answer is C. 0.81.