Final answer:
The average speed is approximately 33.75 mph.
Step-by-step explanation:
The average speed can be calculated by finding the average of the slower and faster speeds. Let's assume the slower speed is 7.5 mph and the faster speed is 60 mph. To find the average speed, add these two speeds and divide by 2:
(7.5 mph + 60 mph) / 2 = 67.5 mph / 2 = 33.75 mph
Therefore, the average speed is approximately 33.75 mph.