1. Understanding Weighted Averages Kathryn H. Zuehlke, Ph.D. Chamblee High School Chamblee, GA Kathryn_H_Zuehlke@dekalbschoolsga.org

2. Calculating Weighted Averages Weighted averages assign more importance to some values than others. Average (Arithmetic Mean) ComponentGrade Labs/Quizzes (33.3%)82 HWK/ClassWk/SF (33.3%)88 Tests/Final (33.4%)67 Average79 Weighted Average ComponentGrade Labs/Quizzes(25%) 82 HWK/ClassWk/SF(45%)88 Tests/Final(30%) 67 Average80 (0.25)82 + (0.45)88 + (0.30)67=80 (0.333)82 + (0.333)88 + (0.334)67=79

3. Calculating Weighted Averages

4. The Weight (wt) of Each Category is Fixed Examples: 8.5 pts earned/10 pts possible x100%=85% 425 pts earned/500 pts possible x 100%=85% 11,460 pts earned/13,482 pts possible x 100%=85% (wt 1)(avg 1)+(wt 2)(avg 2)+(wt 3)(avg 3) = wt avg points earned in category avg for category points possible in category X 100% = Increasing the number of points in a category has no effect on the weight of the category. The average for the category affects the weighted overall grade.

5. Example: Weighting your final exam (3 tests)(50 pts/test)= 150 pts pts on final = total test points (pts on final)(multiplier[ X ])=total test points Some Options: (150 pt final) X =150 test pts, X = 1 (100 pt final) X =150 test pts, X = 1.5 (200 pt final) X =150 test pts, X = 0.75 150 pts

6. Example: Weighting within a category 150 pts 3x50 pts 150 pts Want 3 tests at 50 pts each (pts on test)(multiplier[ X ])=weighted pts of test 1)(42 pts) X = 50 test pts, X = 1.19 2)(54 pts) X = 50 test pts, X = 0.93 3) (38 pts) X = 50 test pts, X = 1.32

7. Decide where assignments will go before entering grades – put in syllabus

8. What If I Only Use 1 or 2 Categories? Percents always total 100 % No summative assessment. 25% + 45% = 70% 25% = 36% During 0.70 45% = 64% Practice 0.70 Desired Only During Learning 25% 0.25 = 100% During

9. Sequence and Multiplier in I.C. Sequence (Seq) groups similar assignments together (LAB=1, QUIZ=2, …EXAM=7)

10. Using the Multiplier in I.C. I had (100 pt final) X =155 test pts, X = 1.55 Select “Multiplier” when printing progress reports