# 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