Ex the average age of students is 20. 3 years old. Where f= frequency or the number of cases in any category n= number of cases in all categories. Compare the number of cases in a specific category to the number of cases in all categori. Compare a par (specific category)to a whole (all categories) Suppose you have 229 people, 97 are female and 132 are male. What is percentage of females in the group. To identify the whole and the part use the keywords of and is (are) F1 - the number of cases in the first category. F2 - number of cases in the second category. There are 60 students there are 33 females and 27 males. How many female students are there compared to male students? gories. Therefore there are 1. 22 females for every male student. Therefore there are 0. 82 male students to every female student.