This one is easier if you think of a real world examples.
If you take a quiz and you get 8 out of 10 questions right, your score is an 80%.
If 6 out of 12 dogs have red collars, then 6/12 have red collars 6/12=1/2 to change in to percent (which means per-one hundred) we have to multiply that answer by 100 .5*100 is 50%
Simply put, you really have a fraction here, 5175/17250 which we can put into a calculator and get 0.3
Again, this is the decimal value in order to change to percent we have to multiply by 100 0.3*100 = 30%
Please let me know if you need any clarifications