Question

Do the data in the table represent a direct variation or an inverse variation write an equation to model the data in the table.

x 1 | 2 | 5 | 10
y 40 | 20 | 8 | 4

A. Direct variation; y=40x
B. Direct variation; y=(1/40)x
C. Inverse variation; xy=40
D. Inverse variation; xy=1/40

Answer 1

The answer is C. xy=40

Answer 2

If we inspect the table we can see that $y$ decreases with $x$ and $xy=40$. Hence the data in the table represents inverse variation.

Since $y=\frac{40}{x}$. $y$ is inversely proportional to $x$.

The correct choice is (C).