Set S consists of integers 7, 8, 10, 12, and 13. If integer n is included in the set, the average (arithmetic mean) of set S will increase by 20%. What is the value of integer n? 7,8,10,12,13 A= Sum/ # of terms A= 10 but when adding n do not get how they get 1.2 i get how you get the arithmetic mean...