Find the mean deviation about the median for the data in Exercises.
The given observations are already in ascending order. We make a table for the given data, as shown below, adding other columns after calculations.
Now, N = 30 which is even.
Median is the mean of 15th and 16th observations. We see that both the 15th as well as the 16th observations lie in the cumulative frequency 21, whose corresponding observation is 30.
Therefore, Median
So, we can calculate the absolute values of the deviations from the median, i.e., |xi – M|, as shown in the table.
Thus, we have
And
Hence, the mean deviation about the median for the given data is 5.1.