Proportion of football players who also play lacrosse:
Number of player who play both football and lacrosse divided by the number of football players.
According to the chart:
There are 16 + 28 = 44 football players.
16 are on the lacrosse team.
16/44 = 0.3636
Percentage:
Proportion multiplied by 100.
0.3636*100 = 36.36%
Your answer is correct :)