To figure out which number is bigger, we must convert them into one form. In this case we will convert the numbers to decimals.
0.831 is already a decimal.
To change the percents into a decimal, you move the percent sign two places to the left and remove the percent sign.
80% => 0.80
84% => 0.84
To convert fractions to decimals, divide the numerator by the denominator.
15/20 = 0.75
After converting all the numbers to a decimal form, you can now see which number is the largest.
And the answer is 84%...