Paper 4: Fundamentals of Business Mathematics & Statistic

FUNDAMENTALS OF BUSINESS MATHEMATICS AND STATISTICS I 5.49

About Median :
Example 47 : The same example as given above.
Table : Computation of Mean deviation (About median)
Marks Cum. Freq. Dev. From median
X f c.f. (15)
| d | f | d |
5 6 6 10 60
10 7 13 5 35
15 8 21 0 0
20 11 32 5 55
25 8 40 (= N) 10 80
Total 40 – – 230

Median = value of the 40 1 2 + th item

= value of 20.5^ th item = 15 marks.

M.D.

f|d| 230

= f = 40

∑

∑ = 5.75 marks

Coefficient of dispersion (about median) =MedianM.D. =5.75 15 = 0.383

(c) For Class Intervals (or Group Distribution)

Steps to compute (M.D.)

(i) Find mid-value of the class intervals

(ii) Compute weighted A.M. or median

(iii) Find | d | and f | d |

(iv) Divide ∑f|d|by∑f

Example 48 : Find M.D. about A.M. of the following frequency distribution :
Daily wages (`) No. of workers
3.50–5.50 6
5.50–7.50 14
7.50–9.50 16
9.50–11.50 10
11.50–13.50 4