Answer:
Please Read below! As a professional athlete, I think I can help. :)
Step-by-step explanation:
First, what is correlation? Correlation is when there is a mutual relationship or connection between two separate things. More studying, better grades. Less sleep, worse focus. In this instance, the football coach wants to see if better leg strength means a faster 40 yard sprint!
As a professional athlete, I can answer immediately that stronger legs, does generally mean a faster sprint. However, this does not mean better endurance in a long distance race!
So the correlation is: stronger legs = faster 40 yard run
A player that can reach 22 leg-presses is likely going to run a faster 40 yard dash, then someone who can only do 10 leg presses. At the same time, however, it's important to take into account the weight of each player, because the person with stronger legs, might have more weight to carry!
I cannot see any chart provided, but I'm going to assume that there is a positive linear graph, with equations being in slope form (y = mx + b).
Let me know if this helps! :)