Standard deviation example:
scores on a midterm
1629.96
1663
76
632.57
37.21
6.1
= 476
x 17
28
26-30
39.93
1.21
1.1
= 759
x 33
23
21-25
288.99
15.21
-3.9
= 342
x 19
18
16-20
475.26
79.21
-8.9
= 78
x 6
13
11-15
193.21
193.21
-13.9
= 8
x 1
8
6-10
0
357.21
-18.9
= 0
x 0
3
1-5
midpt.
interval