University of Delhi 2006-3rd Year B.Com Statistics External Correspondence Previous Year Year : Part II - Question Paper

Q. l. (a) Name the components of time series.

(b) Do you agree that r limits are ranging from one to - one ?

© Show graphically the position of Mean, Median and Mode in a positively and negatively skewed curves.

(d) Why S.D. (Standard Deviation) is considered a better method of variation as compared to M.D. (Mean Deviation)?

(e) Is statistics a science or an art or both?


Q. 2. (a) A distribution consists of 3 components with total frequencies of 200,250 and 300 having means 25,10 and 15 respectively. obtain the mean of combined distribution.

(b) In a series with 100 items, having simply mean of 40, later on it was discovered that 2 items of 45, 35 were wrongly taken as 35 and 25. obtain the accurate mean.

© A man travelled by auto for three days. He covered 480 kilometres every day. He drove the 1st day 10 hours @ 48 kilome¬tres per hour, the 2nd day 12 hours @ 40 kilometres per hour and the 3rd day 15 hours fa) 32 kilometres per hour. What was his avg. speed ?

Q. 3. (a) calculate coefficient of Q.D. and skewness from these values:
Q1 = 14.6
Median = 18.8
Q3 = 25.2

(b) The subsequent is the record of goals scored by team A in a football season:
No. of Goals scored : 0-1-2-3-4
No. of Matches : 1-9-7-5-3

For team B, the avg. number of goals scored per match was 2.5 with a standard deviation of 1.25 goals.

obtain which team may be considered more consistent.

© List the different methods of measuring dispersion. Cal¬culate the value of S.D. (Standard Deviation), if X =45, Mode = 48 and coefficient of skew ness = - 0.4.


Q. 4. (a) describe Index Number. discuss the issues while constructing the index number.

(b) Compute:”
(i) Laspeyre’s;
(ii) Paasche’s;
(iii) Fisher;
(iv) Bowley’s, index numbers from the subsequent tabie:

Items- P0 - q0 - p1 - q1
A - 10 - four - 12 - 6
B - 15 - six - 20 - 4
C - two - five - five - 3
D- four - four - four - 4________

© The correlation ® coefficient ranging from 2 variables is obtained to be 0.75 of 100 items. Comment upon the value of correlation.


Q.5 (a) How many models are used while analyzing the time series State algebraically.

(b) Fit a straight line pattern by method of lowest squares and estimate the for 2006:

Year - 2000 - 2001 - 2002 - 2004 - 2005
Sales - 12 - 13 - 14 - 15 - 26

© From the fallowing data , calculate coefficient of correlation ® ranging from X and Y:

A aeries-Y aeries
- X - 25 - 18

SquareofDeviationsfromA.M. - 136 -, 138

Summation of products of
deviations of X and Y series from
their respective means - 122

Number of pairs of values - 15

Earning:   Approval pending.