1. HOW TO CALCULATE MEAN AND MEDIAN
The Mean and Median are two ways to represent a set of numbers, also called a data set.
The Mean represents the average of the numbers.
The Median represents the middle number.

2. CALCULATING THE MEAN
To calculate the Mean of a set of numbers, you must find their average. This is done by first adding all of the numbers together, then dividing by the amount of numbers you have.

3. CALCULATING THE MEAN
On his first six formal exams, Jose earned grades of 85, 81, 100, 94, 96, and 95. What is the Mean of his exam scores?
First add the numbers:
= 551
Then, divide by the amount of numbers you added:
551 ÷ 6 = 91.83

4. CALCULATING THE MEDIAN
The Median is the middle number. To calculate the Median, put all of the numbers in order from least to greatest.
Then, locate the middle number.

5. CALCULATING THE MEDIAN
In her first 7 high school basketball games, Ashlyn scored 9, 4, 7, 16, 4, 5, and 20 points. What is the median of her points totals?
First, put the numbers in order from least to greatest:
4, 4, 5, 7, 9, 16, 20
What number is in the middle?
The median is 7.

6. CALCULATING THE MEDIAN (part 2)
Sometimes, there are 2 middle numbers. For example, find the median of the following numbers: 4, 7, 11, 3, 4, 6
If we put them in order from least to greatest, we get this: 3, 4, 4, 6, 7, 11.
When you have 2 middle numbers, you must find the mean of those 2 numbers, by adding them together and dividing them by 2.
4 + 6 = ÷ 2 = 5
The median is 5.

7. IN SUMMARY
To find the MEAN of a set of numbers, add them all together, and divide by the amount of numbers you added.
To find the MEDIAN of a set of numbers, order the numbers from least to greatest, then find the middle number.
If there are 2 middle numbers, add them together and divide by 2.

8. MEAN: 25.13 MEDIAN: 10.5 LET’S PRACTICE: 18, 6, 7, 5, 12, 11, 10, 132
Find the mean and the median of the following set of numbers:
18, 6, 7, 5, 12, 11, 10, 132
MEAN: 25.13
MEDIAN: 10.5

9. INTERPRETING THE DATA:
Let’s look again at the data set from the previous slide:
18, 6, 7, 5, 12, 11, 10, 132
Is there a number that doesn’t seem to fit with the rest?
132 is called an Outlier

10. INTERPRETING THE DATA:
Let’s look again at the data set from the previous slide:
18, 6, 7, 5, 12, 11, 10, 132
Mean: Median: 10.5
Which number more accurately reflects the data, the Mean or the Median?