Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum

Session 5, Part D:
Deviations from the Mean

In This Part: Tallying Excesses and Deficits | Line Plot Representations

Use the Interactive Activity or your paper/poster board to display the line plots below (again, for 9 stacks of coins, with a mean of 5).

 Problem D2 Create a line plot with these deviations from the mean = 5: (-4), (-3), (-2), (-1), (0), (+1), (+2), (+3), (+4)

 Problem D3 Create a line plot with these deviations from the mean = 5: (-4), (-2), (-2), (-1), (0), (+1), (+2), (+2), (+4)

 Problem D4 Create a line plot with these deviations from the mean = 5, and specify a set of four remaining values: (-4), (-3), (-3), (-1), (-1)

 Problem D5 How would the line plots you created in Problems D2-D4 change if you were told that the mean was 6 instead of 5? Would this change the degree of fairness of these allocations (as described in Problem B2)?

 When the positive and negative deviations are added together, the total is always 0. This property illustrates another way to interpret the mean: The mean is the balance point of the distribution when represented in a line plot, since the total deviation above the mean must equal the total deviation below the mean.

 Session 5: Index | Notes | Solutions | Video