then we need to find a original number multiplied by the percent and what solution is 20
we wirte a relation
because 8 1/2% is equivalent to 20 and we need to find the 100%
now to find x(missing value) we multiply the diagonal numbers (100 and 20) and divide between 8 1/2
to multiply we transform the mixed number to decimal
and solve
Finally
8 1/2% of 235.3 is 20