The following assignment is worth ten points. Please submit your work in a neat format (no crossing-out). Each answer must show the symbolic formula, numbers inserted in the symbols, answer boxed in.

The following group frequency distribution resulted from scores received on a test on sit-ups per minute given to a high school physical education class:

        X                    f

70-74                          2
65-69                          4
60-64                          7
55-59                          9
50-54                          10
45-49                          12
40-44                          13
35-39                          11
30-34                          7
25-29                          5
20-24                          3

1. Five points:

            Find the score representing the 90th percentile

            Find the score representing the 65th percentil

2. Five points:

        What is the percentile of a score of 42

        What is the percentile of a score of 63