Slope: 60 Interpretation: The speed of the bus is 60mph.
Practice makes perfect
The first thing we notice is that the line passes through origin, which means its y-intercept is 0. Let's write an equation for this line and include the y-intercept in our equation.
y=mx+0 ⇒ y=mx
Now we want to find the slope m of the line. There are a few different ways we can do this. We can substitute either of the given points into the function and solve for m. We could substitute both given points into the Slope Formula. Or we could use the specific characteristic of our graph that we noticed earlier, that the graphs passes through the origin. Let's review the graph again.
Recall that the slope of a line is the ratio of the change in the vertical rise over the horizontal run of the line. Since one of our points is (1,60) and the line passes through the origin, we can determine the slope by just looking at the y-coordinate. Because the x-coordinate is 1 step to the right of the origin and the y-coordinate is 60 steps up from the origin, we can deduce that the slope is 60.
We can now write the equation of the line.
y=60x
We see that the slope is 60. This means that the bus travels 60 miles for each hour it travels. Therefore, the speed of the bus is 60mph.
