1. Measures of Central Tendency (Mean, Median, & Mode)

2. Measures of Central Tendency are used to express an entire data set with one number. All numbers in a set are used to find these measures of central tendency.

3. MEAN (average) Add up all numbers in the data set.
Divide the sum by how many numbers are in the data set.

4. Example: Find the mean of the data set.
14, 16, 12, 24
First, add the numbers = 64
There are 4 numbers in the data set. Divide the sum (64) by 4.
64 ÷ 4 = 20. The mean is 16.

5. MEDIAN (middle number)
Put numbers in order least to greatest.
The middle number is your median.
If there are two middle numbers, add them together and then divide by 2.

6. Find the median of the data set. 19, 25, 13, 17, 16
13, 16, 17, 19, 25
17 is the median.
Find the median of the data set.
9, 7, 3, 6, 5, 2
2, 3, 5, 6, 7, 9
Here, the 5 and 6 are both in the middle = divided by 2 = The median is 5.5.

7. MODE(most) How to find the mode:
Put numbers in order least to greatest.
The number that occurs the most is the mode.
If no numbers repeat, there is NO MODE.
If you have numbers that are tied for the most, they will all be your mode. You can have more than one mode.

8. Example: Find the mode of each data set.
5, 4, 6, 11, 5, 7, 10, 5
15, 3, 8, 9, 0, 1, 20, 7
4, 5, 2, 4, 6, 11, 2, 4, 2

9. Range
Range is a measure of variation. The range tells us the difference in the biggest number (maximum) and the smallest number (minimum) in the data set.
To find the range:
Order the data from least to greatest.
Subtract the smallest number from the largest number.

10. Ex: Find the range of the data set.
20, 17, 24, 31, 30, 24, 19, 18
17, 18, 19, 20, 24, 24, 30, 31
Maximum – Minimum = Range
31 – 17 = 14