Me answer number 4! and if you can, explain!

If Nathan does 9 minutes of push ups for 3 days, that's 9 divided by 3, which is 3. (9/3=3)  So nathan does 3 minutes of push ups each day, so just multiply each day by 3 to find the correlation between the two.

The Table should look like this: 

# of days      # of Minutes
1                     3
2                     6
3                     9
4                     12
5                     15
6                     18 
7                     21

The third and fourth box.