Question

is the average speed related to the maximum or minimum speed of the person

Answer 1

The average speed is based on more than one number. You take all the numbers( in this case speeds of people) add them and divide by the amount of numbers there are. This is how you get an average 

Answer 2

It's related to both.

You can always definitely say that the average is greater than
the minimum and less than the maximum.

But that's ALL you can say is true about EVERY case.