1. Measures of Central Tendency
Mean, Median and Mode
Mean, Median, and Mode
Measures of Central Tendency

2. Mean, Median and Mode What is the mean?
The SUM of the data, divided by the number of items in the set of data ….. commonly called “the average”.

3. The data item that appears the “MOST”
Mean, Median and Mode
What is the mode?
Mean, Median, and Mode
The data item that appears the “MOST”

4. What if the data all appear the same number of times?
Mean, Median and Mode
What if the data all appear the same number of times?
1,1,2,2,3,3,4,4
Mean, Median, and Mode

5. 1,1,2,2,3,3,4,4
Mean, Median, and Mode
There is NO mode

6. Can there be more than one mode?
1,2,2,3,4,4,5,6,7
Mean, Median, and Mode

7. 1,2,2,3,4,4,5,6,7 Yes, there are two modes. What are they? 2 and 4
Mean, Median, and Mode
2 and 4

8. Mean, Median and Mode
What is the median?
Mean, Median, and Mode

9. Reorder from least to greatest
What is the median?
The middle number in the set of data when written “in order” (first step we do)
Given: 2,14,28,0,1,1
Reorder from least to greatest
0,1,1,14,28
The middle number is 1
Mean, Median, and Mode

10. What if you have an even set of numbers?
Given: 10, 0, 20, 30
Reorder from least to greatest
0,10, 20, 30
Add the two middle numbers together.
Mean, Median, and Mode
Divide by 2. What is your median? 15

11. Mean, Median and Mode What is an outlier?
Which will an outlier affect the most: the mean, median or mode? (Hint: Think of class test scores
What is an outlier?
Mean, Median, and Mode
A data item that is far apart from the rest of the data items

12. The difference between the largest and smallest data values
Mean, Median and Mode
What is the range?
Mean, Median, and Mode
The difference between the largest and smallest data values

13. Mean, Median and Mode Let’s try one …
Step 1 – Rewrite in order from least to greatest
Mean, Median and Mode
Let’s try one …
Mean, Median, and Mode
2, 1, 0, 1, 5, 3, 4, 2, 0, 3, 1, 2

14. Mean, Median and Mode
Mean Range 5
Median Mode 1 and 2
Mean, Median, and Mode
2, 1, 0, 1, 5, 3, 4, 2, 0, 3, 1, 2

15. Mean, Median and Mode
Test scores in an Algebra class: 99, 85, 80, 25, 99, 100
What is the mean, median, mode and range?
Mean, Median, and Mode
Mean Median 92
Mode 99 Range 75

16. Mean, Median and Mode
Write a paragraph about what would be your most useful indicator of central tendency in this case: You are ordering a small number of shoes for your shoe store based on the sales of sizes from last year. Write why you made your selection. Why did you not choose the other two?
Mean, Median, and Mode