#### Correlation and Regression Analysis Book Back Questions

11th Standard

Reg.No. :
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Time : 00:45:00 Hrs
Total Marks : 30
5 x 1 = 5
1. Example for positive correlation is

(a)

Income and expenditure

(b)

Price and demand

(c)

Repayment period and EMI

(d)

Weight and Income

2. If the values of two variables move in opposite direction then the correlation is said to be

(a)

Negative

(b)

Positive

(c)

Perfect positive

(d)

No correlation

3. Correlation co-efficient lies between

(a)

0 to ∞

(b)

-1 to +1

(c)

-1 to 0

(d)

-1 to ∞

4. The variable whose value is influenced or is to be predicted is called

(a)

dependent variable

(b)

independent variable

(c)

regressor

(d)

explanatory variable

5. The variable which influences the values or is used for prediction is called

(a)

Dependent variable

(b)

Independent variable

(c)

Explained variable

(d)

Regressed

6. 3 x 2 = 6
7. Calculate the correlation coefficient from the following data
N=9, ΣX=45, ΣY=108, ΣX2=285, ΣY2=1356, ΣXY=597

8. From the following data calculate the correlation coefficient Σxy=120, Σx2=90, Σy2=640

9. The following information is given

 X(in Rs.) Y(in Rs.) Arithmetic Mean 6 8 Standard Deviation 5 $\frac{40}{3}$

Coefficient of correlation between X and Y is $\frac{8}{15}$ . Find (i) The regression Coefficient of Y on X (ii) The most likely value of Y when X =Rs.100.

10. 3 x 3 = 9
11. An examination of 11 applicants for a accountant post was taken by a finance company. The marks obtained by the applicants in the reasoning and aptitude tests are given below.

 Applicant A B C D E F G H I J K Reasoning test 20 58 28 25 70 90 76 45 30 19 26 Aptitude test 30 60 50 40 85 90 56 82 42 31 49

Calculate Spearman’s rank correlation coefficient from the data given above.

12. The following table shows the sales and advertisement expenditure of a form

Coefficient of correlation r= 0.9. Estimate the likely sales for a proposed advertisement expenditure of Rs. 10 crores.

13. Calculate the coefficient of correlation from the following data:
ΣX=50, ΣY=–30, ΣX2 =290, ΣY2 =300, ΣXY=–115, N=10

14. 2 x 5 = 10
15. Find coefficient of correlation for the following:

 Cost(Rs) 14 19 24 21 26 22 15 20 19 Sales(Rs) 31 36 48 37 50 45 33 41 39
16. In a laboratory experiment on correlation research study the equation of the two regression lines were found to be 2X–Y+1=0 and 3X–2Y+7=0 . Find the means of X and Y. Also work out the values of the regression coefficient and correlation between the two variables X and Y.