Question

1 2/3% of it is 4.75

Answer 1

... so 4.75 divided by 1 2/3% is "it".

4.75 * 100 / (5/3) = 285.

So why did I multiply by 100%? 
A "percent" means "one hundredth". If you take 1 2/3% of something you actually multiply by 1 2/3 and then divide by 100. If we go the other direction, you do the opposite!