basically I learned this trick at school, you take the percent, in this case it’s 95/100 and then you write it next to the fraction of what your unit is, so x/20 students
All you need to do is multiply the number if sales by the percentage in decimal form. Using DPR I know that 11% is equal to 0.11, so 4,560(0.11) is 501.60. That can be rounded to 502 sales that were shirts.