Distribution of Exam Scores

For the second exam, the mean raw score was 154 with a dispersion of 21 points.

The grading scale in dispersion units is the folllowing:

• > +2.00 --> A+
• 1.35 -- 2.00 --> A
• +0.95 -- 1.35 --> A-
• +0.50 -- 0.95 --> B+
• +0.20 -- 0.50 --> B
• -0.10 -- +0.20 --> B-
• -0.50 -- -0.10 --> C+
• -1.35 -- -0.50 --> C
• -2.00 -- -1.35 --> C-
• -2.30 -- -2.00 --> D+
• -2.70 -- -2.30 --> D

Your exams on the grading form are reported in raw units. To convert to the equivalent letter score you will have to convert your raw exam score into a dispersion score and use the above guide. Consider this a learning exercise.

Note that the average (0.00) maps into a B-

The distribution: