Text Book Back Questions and Answers
.Calculate the correlation co-efficient for the following data:
Solution:
Coefficient of correlation
Question 2.
Find the coefficient of correlation for the following:
Solution:
Question 3.
Calculate the coefficient of correlation for the ages of husbands and their respective wives:
Solution:
Without deviation:.
N = 10
Coefficient of correlation
Note: We can do the above problem using deviations taken from arithmetic means of X and Y. i.e., using
Question 4.
Calculate the coefficient of correlation between X and Y series from the following data:
The summation of product deviations of X and Y series from their respective arithmetic means is 122.
Solution:
Σx2 = 136, Σy2 = 138, Σxy = 122
Correlation coefficient
Question 5.
Calculate the correlation coefficient for the following data:
Solution:
N = 10, ΣX = 310, ΣY = 340, Σx2 = 870, Σy2 = 720, Σxy = 178
Correlation coefficient
Question 6.
Find the coefficient of correlation for the following:
Solution:
N = 8, ΣX = 600, ΣY = 724, Σdx2 = 1172, Σdy2 = 3372, Σdxdy = -146
Correlation coefficient
Question 7.
An examination of 11 applicants for an accountant post was taken by a finance company. The marks obtained by the applicants in the reasoning and aptitude tests are given below.
Calculate Spearman’s rank correlation coefficient from the data given above.
Solution:
N = 11, Σd2 = 22
Rank correlation
Question 8.
The following are the ranks obtained by 10 students in commerce and accountancy are given below:
To what extent is the knowledge of students in the two subjects related?
Solution:
N = 11, Σd2 = 128
Rank correlation
Question 9.
A random sample of recent repair jobs was selected and the estimated cost and actual cost were recorded.
Calculate the value of spearman’s correlation coefficient.
Solution:
N = 8, Σd2 = 8
Rank correlation
Question 10.
The rank of 10 students of the same batch in two subjects A and B are given below. Calculate the rank correlation coefficient.
Solution:
N = 10, Σd2 = 226
Rank correlation