Find the mean deviation about the mean for the following data
6, 7, 10, 12, 4, 8, 12 and co-eff. of M.D. from mean.
| S.No | x | x - x̄ | |x - x̄| |
| 1 | 6 | -3 | 3 |
| 2 | 7 | -2 | 2 |
| 3 | 10 | 1 | 1 |
| 4 | 12 | 3 | 3 |
| 5 | 13 | 4 | 4 |
| 6 | 4 | -5 | 5 |
| 7 | 8 | -1 | 1 |
| 8 | 12 | 3 | 3 |
n = 8
Σx = 72
Σ|x - x̄| = 22
x̄ = Σx / n = 72 / 8 = 9
Mean Deviation (M.D.) from mean = Σ|x - x̄| / n = 22 / 8 = 2.75
Coefficient of M.D. from mean = M.D. / x̄ = 2.75 / 9 = 0.305 (approx)
