Question

The mean deviation of weights about median for the following data:
Weight (lb): 131-140 141-150 151-160 161-170 171-180 181-190
No. of persons: 3
13
15
is given by
(a) 10.97
(b) 8.23
(c) 9.63
(d) 11.45
​

Answer 1

Mean Deviation of Weights is 10.97

Explanation:

Please follow the Table-I from the file attached.

Where N = 50, So N/2 = 25

Since, 24 < 25 < 39, hence l = 160.5, Cumulative Frequency =24, f = 15 and C = 10

Since we know that, Me = l + { [N/2 - Cf]/f } x C

So, Me = 160.5 + (25 – 24) x10 / 15  

Me = 160.5 + 0.66

Me = 161.66

Consider the II-table in the attached file.

Now, Mean Deviation about the Median = { I xi – Me I fi }/N

MD = 548.68 / 50 = 10