1. A mountain pass rises 0.6 miles over a horizontal distance of 26 miles. A driveway rises 12 feet over a horizontal distance of 150 feet. Which is steeper? (Note: 1 mile = 5280 feet)
2. Which is steeper: a truck ramp that rises 4 feet over a horizontal distance of 9 feet, or a toy truck ramp that rises 3 centimeters over a horizontal distance of 7 centimeters?
3. The circumference, $C$, of a circle is recorded for two radii, $r$: for $r=4$, $C=25.133$, and for $r=10$, $C=62.832$. Calculate the rate of change $\frac{\Delta C}{\Delta r}$. Round to three decimal places. ___
4. What is the slope of the line that passes through the points $(2, 4)$ and $(5, 13)$? The slope is ___.
5. Find the slope of the line that contains the points $(-3, 7)$ and $(5, 3)$. Give your answer as a fraction. The slope is ___.
6. The slope of a line is defined as the ratio of which two quantities?
7. A line passes through the points $(50, 25)$ and $(70, 85)$. Calculate the slope of the line. The slope is ___.
8. What is the slope of any vertical line?
9. Which line is decreasing: one with a slope of $\frac{1}{4}$ or one with a slope of $-2$?