FUNDAMENTALS OF BUSINESS MATHEMATICS AND STATISTICS I 5.63Q 1 lies in the class 20 - 40
Q 1 =
N cf
L^4 i
f−
+ ×
=^20 +^2 0 8 12 − ×^20
= 20 + 20 = 40
Q 3 = Size of 3N 4 th item
= Size of 3 80× 4 = 60th itemQ 3 lies in the class 60 - 80
Q 3 = 1
3 N cf
L^4 i
f−
+ ×
=^60 +^6 0 50 20 − ×^20
= 70
Co-efficient of Q.D =^7 70 40 1100 40−+ =^30 =0.27
SELF EXAMINATION QUESTIONS
(A) Regarding Range.
- Daily wages in
of 7 workers are as follows : () : 12, 8, 9, 10, 7, 14, 15. Calculate range. [Ans. ` 8] - Find range :
Weight (kg) : 40, 51, 47, 39, 60, 48, 64, 61, 57. [Ans. 25 kg] - The marks obtained by 6 students are 24, 12, 16, 11, 40, 42. Find range. If now the highest mark is
omitted, find the percentage change in range. [Ans. 31 marks, 6.45]
(B) Regarding MEAN DEVIATION :
- Find Mean Deviation about mean of the numbers given :
(i) 31, 35, 29, 63, 55, 72, 37. [Ans. 14.9]
(ii) 29, 35, 51, 63, 78, 106, 128 [Ans. 29.143] - Find M.D. about median of :
13, 84, 68, 24, 96, 84, 27. [Ans. 32.286]