1. Unit 7. Day 13.

2. We need a representative number
4, 16, 16, 1, 4, 6, 3, 3, 2, 4, 5, 1, 5, 6, 2, 3, 5, 4
We need a representative number
Is the data is located near the center?
Is the data is located near the center or is the data is spread out?
(Best representative comes form the center)
Measures of Central Tendency
Measures of
Variability/Dispersion/Spread
MEAN (average)
Range
Inter-Quartile Range (IQR)
MEDIAN
Mean Absolute Deviation (MAD)
MODE

3. Do dot plot only for Examples A & B
Q: Do you think they will have similar centers?
Q: Do you think they will have similar variability?

4. Example A: 13, 5, 6, 1, 6, 6, 4, 15, 7, 0, 9, 5, 2, 7, 4
Example B: 10, 12, 20, 5, 8, 9, 13, 10, 6, 12, 19, 11, 11, 9, 10

5. Calculate the measures of center and variability
Measures of Central Tendency
Measures of Variability
Mean:
Range:
Median:
IQR:
Mode:
MAD:

6. Example A: 13, 5, 6, 1, 6, 6, 4, 15, 7, 0, 9, 5, 2, 7, 4
Mean: 13 + 5 + 6 + 1 + 6 + 6 + 4 + 15 + 7 + + 9 + 5 + 2 + 7 + 4 18
90 15 = 6
Median: 6
0, 1, 2, 4, 4, 5, 5, 6, 6, 6, 7, 7, 9, 13, 15
Mode: 6

7. Bonus: Inter-Quartile Range: 7 − 4 = 315 − = 15
Quartiles
0, 1, 2, 4, 4, 5, 5, 6, 6, 6, 7, 7, 9, 13, 15 UQ LQ
Bonus: Inter-Quartile Range: 7 − 4 = 3
Mean Absolute Deviation:

8. Mean Absolute Deviation: 6
13, 5, 6, 1, 6, 6, 4, 15, 7, 0, 9, 5, 2, 7, 4 2 10 12 14 16 1 3 4 6 8 18
Mean Absolute Deviation: 6 + 5 + 4 + 2 + 2 + 1 + 1 + + + + 1 + 1 + 3 + 7 + 9 15
42 15 =
2.8

9. Example B: 10, 12, 20, 5, 8, 9, 13, 10, 6, 12, 19, 11, 11, 9, 10
Mean: 10 + 12 + 20 + 5 + 8 + 9 + 13 + 10 + 6 + 12 + 19 + 11 + 11 + 9 + 10 15
165 15 = 11
Median: 10
5, 6, 8, 9, 9, 10, 10, 10, 11, 11, 12, 12, 13, 19, 20
Mode: 10

10. Bonus: Inter-Quartile Range: 12 − 9 = 320 − 5 = 15
Quartiles
5, 6, 8, 9, 9, 10, 10, 10, 11, 11, 12, 12, 13, 19, 20 UQ LQ
Bonus: Inter-Quartile Range: 12 − 9 = 3
Mean Absolute Deviation:

11. 10, 12, 20, 5, 8, 9, 13, 10, 6, 12, 19, 11, 11, 9, 10
Mean: 11 10 12 14 16 1 2 3 4 6 8 18
Mean Absolute Deviation: 1 + 2 6 + 5 + 3 + 2 + 2 + 1 + 1 + 1 + + + 1 + + 8 + 9 15
42 15 =
2.8

12. 13, 5, 6, 1, 6, 6, 4, 15, 7, 0, 9, 5, 2, 7, 4
Mean: 6
Range: 15
Equally spread out
Median: 6
IQR: 3
Equally spread out
Mode: 6
MAD: 2.8
Equally spread out
10, 12, 20, 5, 8, 9, 13, 10, 6, 12, 19, 11, 11, 9, 10
Mean: 11
Range: 15
Equally spread out
Median: 10
IQR: 3
Equally spread out
Mode: 10
MAD: 2.8
Equally spread out