Question

Amy's grade was the 90th percentile of the 80 grades for her class. Of the 100 grades from another class, 19 was higher than Amy's and the rest was lower. If no other grade is the same as Amy' grade, then Army's grade was what percentile of grades of two class combined.

Answer 1

Army's grade was 85 percentile of grades of two class combined.

Explanation:

Consider the provided information.

It is given that Amy's grade was the 90th percentile of the 80 grades for her class.

The means the number of classmate is:
`80*0.9=72`.

Of the 100 grades from another class, 19 was higher than Amy's and the rest was lower.

100−19=81 students

So, in combined classes she outscored 72+81=153

The total number of students are 80+100= 180

`(153)/(180)=0.85`

Hence, Army's grade was 85 percentile of grades of two class combined.