Question

The table below shows y, the average speed of a cyclist in miles per hour, and x, the time in hours that it takes the cyclist to complete a bicycle tour. Which rational function best models the data in the table?

Time, x
(hours)
Average Speed, y
(miles per hour)
12
8
16
6
mc008-1.jpg
9
18
mc008-2.jpg
mc008-3.jpg
mc008-4.jpg
mc008-5.jpg
mc008-6.jpg

Answer 1

Because the speed and time are inversely related, y = k/x. Use one data point to find k: k = x·y = 12·8 = 96.
So the rational model is y = 96/x. (Check: 96/16 = 6, which matches the table.)