Find the mean deviation about the mean for the following data.
| xi | 16 | 8 | 5 | 15 | 13 | |
| fi | 3 | 8 | 10 | 5 | 9 | 12 |
| xi | fi | fixi | |xi - μ| | fi|xi - μ| |
| 1 | 3 | 3 | 8.5 | 25.5 |
| 8 | 8 | 48 | 1.5 | 28 |
| 9 | 5 | 45 | 0.5 | 2.5 |
| 10 | 25 | 250 | 0.5 | 12.5 |
| 13 | 12 | 156 | 3.5 | 49.5 |
| 47 | 447 | 182.5 |
N = Σfi = 47
Σfixi = 447
Σfi|xi - μ| = 182.5
∴ μ = 447/47 = 9.5
Mean Deviation (μ) = 182.5/47 = 3.9