So, the rate of change is basically the slope and how do we find the slope? Rise over run, which is how much the y value changes over how much the x value changes. In this case, the y value goes from 10 to 15, which means it has rose 5 times, so the top number of your fraction for slope would be 5. Then, the x value goes from 4 to 6, so the denominator would be 2. The slope is 5 miles over 2 minutes. To find out how many miles per one minute, you need to get the denominator to 1, do this by dividing it by 2. Of course, you also have to divide the numerator by 2, which equals 2.5. So, the rate of change is 2.5 miles per minute, or C. Hope this helps!
