Chapter 11 - Rational Expressions and Functions - 11-6 Inverse Variation - Practice and Problem-Solving Exercises - Page 703: 26

Inverse variation The equation is $xy = 60$.

The values of y seem to vary inversely with the values of x. Ratio: $4\times15=60$ $10\times6=60$ $6\times10=60$ The ratio $\frac{y}{x}$ is the same for all data pairs. So this is inverse variation, and $k =60$. An equation is $xy = 60$.