All the % sign is is another way of denoting hundredths, so 45 1/2% and 45 1/2 hundredths are the same thing. With this knowledge, We can write it as a fraction like this:
Converting the mixed number 45 1/2 to the improper fraction 91/2, we now have:
Dividing a number by 100 is the same thing as multiplying it by 1/100, so we can rewrite this complex fraction as the product
91/200 is irreducible, so we have our answer.