2. First Quartile- Q1
The middle of the lower half of data

3. Third Quartile- Q3
The middle of the upper half of data

4. Interquartile Range- IQR
Q3 – Q1 = IQR

5. Mean x (the average)
Add up all of the data, then divide by the total number of data points
Ex: 5, 10, 20, 25, 35
= = 19

6. Median- Q2 (the middle data point)
To find the middle of the data:
First put the data in numerical order from lowest to highest
Then mark off from each end till you reach the middle
If there are two numbers left in the middle then you add them up and divide by 2. The answer is the median.

7. Mode- the data that occurs most often
If every number occurs only once there is NO MODE
There can be more than one mode if multiple numbers occur the same amount of times

8. To put data in calculator:
Press data button
You should have 3 columns
Enter your information by hitting the numbers and enter
When you are done entering the data, hit 2nd data, then 1-var stats, then enter, enter, enter, enter
You should see n= and x=

9. MAD for #1 |12-19|+|27-19|+|15-19|+|23-19|+|18-19| 5 7+8+4+4+1 = 24
= 24