8. Find the mean deviation about the median.
15 | 3 | 3 | 13.5 | 40.5 |
21 | 5 | 8 | 7.5 | 37.5 |
27 | 6 | 14 | 1.5 | 9 |
30 | 7 | 21 | 1.5 | 10.5 |
35 | 8 | 29 | 6.5 | 52 |
Now, N = 30, which is even.
Median is the mean of and observations.
Both these observations lie in the cumulative frequency 21, for which the corresponding observation is 30.
Therefore, Median, M
Now, we calculate the absolute values of the deviations from median, and
= 149.5
Hence, the mean deviation about the median is 5.1