## Intermediate Algebra (6th Edition)

$\approx-.12$
The slope measures the ratio of the vertical change to the horizontal change between 2 points on a line. We can write the slope as m= (vertical change)/(horizontal change) In this example, the vertical change of the mountain is -1600 feet and the horizontal change is 2.5 miles. Since we know that 2.5 miles is $2.5\times5280=13200$ feet Therefore, $m=\frac{-1600}{13200}\approx-.12$