Answer :

So the question asks for the cyclist's mph, which we'll call x. so if 4x = 72 then x = 72/4 so if we divide 72 by 4, x= 18 The cyclist travels at 18 mph

Answer:    18 mph

Explanation:  The average speed per hour can be calculated if we know the total distance the cyclist has gone through, and for what time has passed that distance. This means that the cyclist did not drive at the same speed every hour, it probably changed from hour to hour, depending on the terrain conditions, but in any case, the average speed for the whole trip can be obtained. So the average speed is obtained when the total distance is divided with the time it takes to pass that distance:

speed = 72 miles / 4 hours = 18 mph