1. Graphs Histogram, Circle, Box-Whisker
Cornell Notes #11
Central Tendency Review

2. Choosing the Best Measure
Which central tendency best represents a data set.
Mean is usually the best choice.
HOWEVER: if there is a outlier ( a number that is much lower or higher than the others) the median or mode is a better choice.

3. Choosing the Best Measure
Example: The data set represents the number of customers that came into the restaurant last week.
We want to estimate the number of customers that will come into the restaurant next week.
Data Set: 88, 220, 253, 305, 306, 310, 310
Mean: 256
Median: 305
Mode: 310
Since there is an outlier (88), the mean is not the best choice.
Median, Mode: best

4. Practice:
The following data set shows the number of free throws Jordan had in each of his 12 years playing basketball.
67, 26, 20, 93, 78, 88, 79, 99, 64, 75, 74, 10
Is the mean, median, or mode best to use to describe this data set? Explain.
Data Set: 10, 20, 26, 64, 67, 74, 75, 78, 79, 88, 93, 99
Mean: Median: Mode: none
Mean: not a good choice- outlier of 10
Mode: none
Median: best choice

5. Representations of Data
In this lesson, you will take notes on how to construct and interpret histograms and circle graphs. You will also learn how to choose the best graph to represent different types of data.

6. Circle Graphs
Circle Graph
Graphs that represents parts of a whole.
Sum of the angle measures equal 360˚
Multiply the percent in each section by 360 to find the angle measure.

7. Find the number of each of the equations.
Circle Graphs
Find the number of each of the equations.
Convert the percent to a decimal. 40% to a decimal 40 ÷ 100=.40
8% to a decimal ÷ 100=.08
40% of 25=
25% of 30=
67% of 66=
8% 0f 23=
10% of 100
1% of 56=

8. 200 boxes of fruit were sold. 27% apples 8% grapes 3% pears
Circle Graphs
Example:
200 boxes of fruit were sold.
27% apples
8% grapes
3% pears
40% oranges
22% other
Percent’s equal 100%
Find the number of boxes of each fruit.
200 X 27% (.27)
54 boxes of apples
200 X 8% (.08)
16 boxes of grapes
200 X 3% (.03)
6 boxes of pears
200 X 40% (.40)
80 boxes of oranges
200 X 22% (.22)
44 boxes of other fruit

9. 200 boxes sold: what percent of apples sold?
Circle Graphs
Example:
200 boxes sold: what percent of apples sold?
To find the percent sold:
Number sold ÷ total=% of total.
54 boxes of apples:
54 ÷ 200=.27 or 27%
6 boxes of pears:
6 ÷ 200=.03 or 3%
.03 X 100=3%

10. Sum of all fruit is 100%

11. Histograms
Histograms
Used to show continuous data.
Intervals are shown across the bottom.
The heights of the bars shows how many times something happens.

12. Histogram Example: Score between 0 and 10 occurred 1
time, occurred 2 times (range of scores)

13. Summary Graphs Histogram Circle graph Box-and –whisker plot
Representation
Purpose of data
Histogram
Comparing amounts of continuous data:
Type of bar graph
Circle graph
Comparing parts of a whole
Sum of all parts is 100%
Box-and –whisker plot
Showing how data are distributed