MTH302 Business Mathematics & Statistics Assignment 2 Solution Spring 2013

Q#1:

Using the co-efficient of variation, determine whether or not there is greater variation among the prices of certain similar commodities, than among the life in hours under test.

Prices in Rupees: 8, 13,18,23,30,         Life in hours: 130,150,180,250,350

 

Prices in Rs. X Life in hours Y    
   

8

130

64

16900

13

150

169

22500

18

180

324

32400

23

250

529

62500

30

350

900

122500

=92

1060

=1986

=256800

 

Price of commodities                                     Life in hours

We see that the co-efficient of varition for the prices of commodities (X) is larger than that for the life in hours (Y).Hence the price of certain similar commodities are showing greater variation than that among the life in hours under test.

Q#2:

Grades of Punjab University students in the final thesis of BS-project according to the number of hours of study are recorded as follows:

 

Students No. of hours(X) Grades(Y)

1

1

60

2

2

65

3

2

70

4

4

81

5

5

85

6

7

89

7

7

95

8

8

80

9

9

82

10

9

92

 

(a)Compute coefficient of Correlation.

(b)Determine whether the coefficient of correlation is positive, negative or there is no correlation between the measured values.

 

SOLUTION:

Students

No. of hours(X)

Grades(Y)

XY

1

1

60

1

3600

60

2

2

65

4

4225

130

3

2

70

4

4900

140

4

4

81

16

6561

324

5

5

85

25

7225

425

6

7

89

49

7921

623

7

7

95

49

9025

665

8

8

80

64

6400

640

9

9

82

81

6724

738

10

9

92

81

8464

828

=54

=799

=374

=65045

=4573

(b) Determine whether the coefficient of correlation is positive, negative or there is no correlation between the measured values.

Answer:  The coefficient of correlation is positive

 

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