Lesson 9: Describe Data by Mean Absolute Deviation6.DS.6c

I can…

I can find the mean absolute deviation (MAD) to describe how spread out data is.

Key words

• Mean Absolute Deviation — The typical distance of the data from the mean.
• Deviation — How far a number is from the mean.
• Absolute Value — How far a number is from zero.
• Spread — How far apart the numbers are.
• Data distribution — Where the values sit and how far apart they are.
• Variability — How far apart the numbers are.
• Mean — Add all the numbers, then divide by how many.
• Variation — How much the values vary.

Steps

1. My data set: 6, 8, 10, 12. First I find the mean: 6 + 8 + 10 + 12 = 36, then 36 ÷ 4 = 9. The mean is 9.
2. Next I find each deviation (value − mean): 6−9 = −3, 8−9 = −1, 10−9 = 1, 12−9 = 3.
3. Then I take the absolute value of each (the distance, never negative (zero is allowed)): 3, 1, 1, 3.
4. Finally I average those distances: 3 + 1 + 1 + 3 = 8, then 8 ÷ 4 = 2. So the MAD = 2 points.

Try it

Next, you will find the MAD for Player A's scores step by step in the table.

Check your answer

Check with your guided notes.

Sentence starter

I know ___ because ___.

Goal: I can explain my work using the words mean absolute deviation, deviation, absolute value, and spread.