To do this, we first want to see how many participants there are in total by adding both males and females.
[tex]99+121=220[/tex]
Now we know that there were 220 total participants, but only 121 were females.
This allows us to set up the fraction 121/220= the percent female.
[tex]\frac{121}{220} =0.55[/tex]
or 55%
