1. Warm Up  Find the mean of the following: 12, 3, 5, 9, 21 5, 7 271, 35, 106, 243 20, 30, 10, 50 1, 2, 3

2. Agenda  Warm Up (10)  Notes (20)  EQ  Task “Sad to Mad” (30)  Practice Problems (20)  Ticket out the Door  Homework

3. Notes  Standard: MA1D4. Students will explore variability of data by determining the mean absolute deviation (the averages of the absolute values of the deviations).  Key Vocabulary Mean-average Mode-number that occurs the most Median-the middle number Summation MEAN ABSOLUTE DEVIATION (MAD)

4. Summation  Summation – add the series or sequence of numbers. Symbol: Example:

5. Mean Absolute Deviation (MAD)  The (MAD) is used as a way to determine the variability of data. Variability means the variance (spread) in different things such as test scores, results, or other data.  The formula to find the mean absolute Deviation:

6. Essential Question (EQ)  How can I quantify the variability of a distribution?

7. Task  “Sad to Mad”

8. Practice--Find the MAD Find the MAD of 1, 1, 4, 7, 12  Step 1: Find the mean ( ) (1+1+4+7+12)÷5= 5  Step 2: Sum the absolute deviations from the mean ( ) |1-5|+|1-5|+|4-5|+|7-5|+|12- 5|=4+4+1+2+7=18  Step 3: Divide by the number of data points ( ) 18/5=3.6

9. Ticket out the Door  Describe how you would find the MAD of a set of numbers.