The percentage of registered voters that voted are
[tex]\frac{\text{voted}}{\text{registered voters }}\times100[/tex]Now,
# voted = 121,621,050
# registered voters = 190,296,524;
therefore,
[tex]\text{percent}=\frac{121,621,050}{190,296,524}\times100=63.91\approx64[/tex]Hence, about 64% of the registered voters voted.