# Dibrugarh University - Business Statistics 2011

1.       (a)  Write down the differences between primary data and secondary data.
(b)  Calculate mean and variance from the following data:
 X     : 0-10 10-20 20-30 30-40 40-50 F      : 1 4 10 22 30

OR

(c) What is the difference between absolute and relative measure of dispersion? Find the missing frequency from the following distribution when median is 32.5 marks:

 Marks   : 10-20 20-30 30-40 40-50 50-60 No. of students: 3 5 ---- 3 1

(d) Calculate from the following (i) Geometric mean (ii) Median and (iii) Mode:
5,2,2,3,4,4,1

2.       (a)  What is regression line? Why are there two lines of regression?
(b)  Calculate Karl Pearson’s coefficient of correlation from the following:
N=10     ∑X=140   ∑Y=150
∑(X-10)2=180      ∑(Y-15)2=215
∑(X-10) (Y-15) =60

Or

(c)   Write down the difference between correlation and regression.
(d)  Calculate coefficient of correlation from the following data:

 Value of X: 1 2 3 4 5 6 7 8 9 10 Value of Y: 46 42 38 34 30 26 22 18 14 10

3.       (a)  Define index number and state its uses.
(b)  Why is Fisher’s index number called ideal index number? Calculate Fisher’s index number? Calculate Fisher’s index number from the following data:
 Commodity Price 2003 Quantity 2003 Price 2005 Quantity 2005 A B C D E 8 10 5 4 4 10 12 8 14 5 10 12 8 14 5 12 8 5 3 25

Or
(c)   State the limitations of index number.
(d)  Calculate (i) price index (according to Laspeyres’ formula) and (ii) quantity index (according to Paasche’s index) using the following table:

 Commodity P0 q0 P1 q1 A B C 4 2 6 6 4 2 6 4 2 4 2 6

4.    (a)  From the following table, calculate trend values by 3-yearly weighted moving averages
With weight 1, 2, 2 respectively:

 Year: 1 2 3 4 5 6 7 Sales(Rs.) 2 4 5 7 8 10 13

(b)  Discuss the components of a time series.

Or

(c)   Find the trend values by 3-yearly moving average method from the following data:

 Year: 1960 1961 1962 1963 1964 1965 1966 1967 1968 Sales: 5 7 9 12 11 10 8 12 13
(d) Discuss the methods of measuring trends.

5.    (a)  Mention the purpose and assumptions of business forecasting.
(b)  Discuss any three methods of forecasting.
Or
(c)   Explain the concept of business forecasting.
(d) Explain sales forecasting and demand forecasting.

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