Formula is applied to get median.
Where N is the sum of frequencies, l, f, h and C are, respectively the lower limit, the frequency, the width of the median class and C the cumulative frequency of the class just preceding the median class
Once median is obtained, just apply Mean deviation formula.
Limitations of mean deviation Sample A: 2, 2, 2, 2,-2,-2,-2,-2 Sample B: 3, 1, 3, 1,-3,-1,-3,-1
MeanA = MeanB = 0 Mean Deviation about mean for A, B are equal. i. e 2 Variance:
Sample A: 2, 2, 2, 2,-2,-2,-2,-2 Sample B: 3, 1, 3, 1,-3,-1,-3,-1 Mean for both Sample A & B is 0. Aslo number of terms, N in both case is 8.