Suppose your data is in A1:A100 and has values in range 0 to 100
1) In C1:C10 enter 10,20, 30...100  This is called the BIN
2) Select D1:D10, type =FREQUENCY(A1:A100, C1:C10, and press
SHIFT+CTRL+ENTER
If all your numbers are the same or you just get value in D1 you did not
follow instructions!
Now you have the frequency data: D1 is count of data in A1:A100 that is 10
or less; D2 is count for 11 to 20
3) In E1 enter =D1/COUNT($A$1:$A$1000); format as %; copy down the column to
E10
Now you have relative frequency

I want 1/2 of the grade we get for the assignment!