Just look at the percentages and make them into fractions. You can think about it like money. 50 cents is half of a dollar, so %50 is 1/2. for the decimals, you just take the percent and put a decimal point in front of the answer, so 28% is .28, 50% is .50, 18% is .18. For fraction to decimals, you could just put 1 divided by 4 into a calculator and it will tell you .25, which is the decimal, and 25 cents is one fourth of a dollar, so it works out.
Hope this helps! Let me know if you have any more questions!