 Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum            Session 5, Part C:
Using Line Plots

In This Part: Creating a Line Plot | Means from the Line Plots
Balancing Excesses and Deficits

In the previous examples, you explored line plot representations for sets of 45 coins, each in 9 stacks. For each allocation the mean was 5 coins. Now let's use these line plot representations to explore another way to interpret the mean.  Problem C4 Here is a line plot corresponding to an allocation of 45 coins in 9 stacks: From this line plot, we can see that there are 3 stacks containing exactly 5 coins each, and 1 stack containing 6 coins. The maximum number of coins in a stack is 8, and the minimum is 2.

Rearrange the nine dots to form a line plot with each of these requirements:

 a. Form a different line plot with a mean equal to 5. b. Form a line plot with a mean equal to 5 that has exactly 2 stacks of 5 coins. c. Form a line plot with a mean equal to 5 but a median not equal to 5. d. Form a line plot with a mean equal to 5 that has no 5-coin stacks. e. Form a line plot with a mean equal to 5 that has two 5-coin stacks, 4 stacks with more than 5 coins, and 3 stacks with fewer than 5 coins. f. Form a line plot with a mean equal to 5 that has two 5-coin stacks, 5 stacks with more than 5 coins, and 2 stacks with fewer than 5 coins. g. Form a line plot with a mean equal to 5 that has two 5-coin stacks, two 10-coin stacks, and 5 stacks with fewer than 5 coins.  Don't forget that the mean must always be equal to 5. If you move a dot to the right, it will increase the mean. Each time you move a dot to the right, you must balance this by moving another dot an equal distance to the left. Also, keep in mind that each dot represents a stack of coins, and that by moving the position of the dot, you change the number of coins in the stack. The total number of coins must remain 45.   Close Tip Don't forget that the mean must always be equal to 5. If you move a dot to the right, it will increase the mean. Each time you move a dot to the right, you must balance this by moving another dot an equal distance to the left. Also, keep in mind that each dot represents a stack of coins, and that by moving the position of the dot, you change the number of coins in the stack. The total number of coins must remain 45.   Session 5: Index | Notes | Solutions | Video