1. Define the following words in your own definition
WARM UP
Define the following words in your own definition
Mean
Median
Mode
Range

2. Define the following words in your own definition
WARM UP
Define the following words in your own definition
Mean – the average of a set of data
Median- the number that is in the middle when the
data is in order
Mode- the number that appears the most
Range- the difference between the largest and
smallest number

3. Box-and-Whisker Plots

4. Step 1 – Order Numbers
1. Order the set of numbers from least to greatest

5. Step 2 – Find the Median
2. Find the median. The median is the middle number. If the data has two middle numbers, find the mean of the two numbers. What is the median?

6. Step 3 – Upper & Lower Quartiles
3. Find the lower and upper medians or quartiles. These are the middle numbers on each side of the median. What are they?

7. Step 4 – Draw a Number Line
Now you are ready to construct the actual box & whisker graph. First you will need to draw an ordinary number line that extends far enough in both directions to include all the numbers in your data:

8. Step 5 – Draw the Parts
Locate the main median 12 using a vertical line just above your number line:

9. Step 5 – Draw the Parts
Locate the lower median 8.5 and the upper median 14 with similar vertical lines:

10. Step 5 – Draw the Parts
Next, draw a box using the lower and upper median lines as endpoints:

11. Step 5 – Draw the Parts
Finally, the whiskers extend out to the data's smallest number 5 and largest number 20:

12. Step 6 - Label the Parts of a Box-and-Whisker Plot
Lower Quartile
Median
Upper Quartile
Lower Extreme 3 1 2
Upper Extreme 4 5
Name the parts of a Box-and-Whisker Plot

13. 14 – 8.5 = 5.5 Interquartile Range
The interquartile range is the difference between the upper quartile and the lower quartile.
14 – 8.5 =
5.5

14. Are There Any Outliers?
Using the 1.5*IQR Rule

15. Say we have the following data: 1,2,5,5,7,8,10,11,11,12,15,20
Notice that you must have ordered data before you can find the Five – Number – Summaries.
Find the median first. It’s the middle point.
Then find the quartiles, Q1 and Q3. They are the middles of the lower and upper half, respectively.
The last thing to do is determine whether there are outliers using the 1.5*IQR Rule

16. min Q Q max ,2,5,5,7,8,10,11,12,12,18,25 1 5 9 12 18 25
-5.5
22.5
1.5IQR
IQR = 12 – 5 = 7
1.5IQR
* 7 = -5.5
* 7 = 22.5
25 is considered an outlier and will be a point in a boxplot and the ‘whisker’ ends at the last non-outlier data point.