Anticipatory Set:
Find each quotient
1. 60 / (-15)
2. -16.8 / (-3)
Simplify each expression
3. (64x)/4
4. (7w - 28)/(-7)
5. Hank used a total of 5 5/8 cups of sugar to make 3 identical cakes. How much sugar did he use for each cake?
6. If (-40)/(-10) = n, what is the value of 10n - 4?
Lesson Notes
Line Plot: visual representation of frequencies in the data
Frequency: how often a value occurs in the data.
Create a Line Plot:
Step 1: Find the range of data
Step 2: Construct a number line
Step 3: Put an x above the number of times the value occurs
Example 1:
A. Draw a line plot for the data
11, -2, 10, -2, 7, 2, 4, 9, 0, 6, 9, 7, 2, 0, 4, 10, 7, 6, 9
B. use the line plot to determine which value occurs most frequently
Stem and Leaf Plot:
stem: greatest common place
leaf: remaining part of value
Class Example
Example 2: Create a stem and leaf plot for the following data
| 85 | 115 | 126 | 92 | 104 | 107 | 78 | 131 | 92 | 116 |
| 100 | 121 | 123 | 131 | 88 | 97 | 99 | 116 | 90 | 110 |
| 108 | 93 | 84 | 75 | 70 | 130 | 79 | 114 | 85 | 129 |
Back-to-back stem-and-leaf plots
* done the same way, but the leaves are on both sides of the stem
* each side representing a different set of data
* used to compare sets
Example 3:
a) Make a stem-and-leaf plot to compare the data
b) Which city has higher temperatures?
| Monthly Average High Temperatures | |||||||
| Dallas | Atlanta | ||||||
| 54 | 59 | 68 | 77 | 50 | 55 | 64 | 72 |
| 83 | 91 | 95 | 95 | 75 | 85 | 88 | 87 |
| 87 | 78 | 66 | 57 | 81 | 72 | 63 | 54 |
Measures of Central Tendency
Mean: sum of values divided by the total number of values (average)
Median: middle value
Mode: value occuring the most often
Example 4: Which measure of central tendency best represents the data?
| Stem | Leaf |
| 4 | 1 1 2 4 4 5 8 |
| 5 | 0 |
| 6 | 2 5 7 |
| 7 | 3 9 |
| 8 | 1 |
Homework: WS 2-5 Practice