Tamilnadu State Board New Syllabus Samcheer Kalvi 11th Business Maths Guide Pdf Chapter 9 Correlation and Regression Analysis Ex 9.3 Text Book Back Questions and Answers, Notes.

## Tamilnadu Samacheer Kalvi 11th Business Maths Solutions Chapter 9 Correlation and Regression Analysis Ex 9.3

### Samacheer Kalvi 11th Business Maths Correlation and Regression Analysis Ex 9.3 Text Book Back Questions and Answers

Choose the correct answer.

Question 1.

An example of a positive correlation is:

(a) Income and expenditure

(b) Price and demand

(c) Repayment period and EMI

(d) Weight and Income

Answer:

(a) Income and expenditure

Question 2.

If the values of two variables move in the same direction then the correlation is said to be:

(a) Negative

(b) Positive

(c) Perfect positive

(d) No correlation

Answer:

(b) Positive

Question 3.

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

(a) Negative

(b) Positive

(c) Perfect positive

(d) No correlation

Answer:

(a) Negative

Question 4.

Correlation co-efficient lies between:

(a) 0 to ∞

(b) -1 to +1

(c) -1 to 0

(d) -1 to ∞

Answer:

(b) -1 to +1

Question 5.

If r(X, Y) = 0 the variables X and Y are said to be:

(a) Positive correlation

(b) Negative correlation

(c) No correlation

(d) Perfect positive correlation

Answer:

(c) No correlation

Question 6.

The correlation coefficient from the following data N = 25, ΣX = 125, ΣY = 100, ΣX^{2} = 650, ΣY^{2}= 436, ΣXY = 520:

(a) 0.667

(b) -0.006

(c) -0.667

(d) 0.70

Answer:

(a) 0.667

Hint:

Question 7.

From the following data, N = 11, ΣX = 117, ΣY = 260, ΣX^{2} = 1313, ΣY^{2} = 6580, ΣXY = 2827. the correlation coefficient is:

(a) 0.3566

(b) -0.3566

(c) 0

(d) 0.4566

Answer:

(a) 0.3566

Hint:

Question 8.

The correlation coefficient is:

Answer:

(b) r(X, Y) = \(\frac{cov(x, y)}{\sigma_{x} \sigma_{y}}\)

Question 9.

The variable whose value is influenced or is to be predicted is called:

(a) dependent variable

(b) independent variable

(c) regressor

(d) explanatory variable

Answer:

(a) dependent variable

Question 10.

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

(a) Dependent variable

(b) Independent variable

(c) Explained variable

(d) Regressed

Answer:

(b) Independent variable

Question 11.

The correlation coefficient:

Answer:

(a) \(r=\pm \sqrt{b_{x y} \times b_{y x}}\)

Question 12.

The regression coefficient of X on Y:

Answer:

(a) \(b_{x y}=\frac{\mathrm{N} \Sigma d x d y-(\Sigma d x)(\Sigma d y)}{\mathrm{N} \Sigma d y^{2}-(\Sigma d y)^{2}}\)

Question 13.

The regression coefficient of Y on X:

Answer:

(c) \(b_{y x}=\frac{\mathrm{N\Sigma} d x d y-(\Sigma d x)(\Sigma d y)}{\mathrm{N} \Sigma d x^{2}-(\Sigma d x)^{2}}\)

Question 14.

When one regression coefficient is negative, the other would be:

(a) Negative

(b) Positive

(c) Zero

(d) None of these

Answer:

(a) Negative

Question 15.

If X and Y are two variates, there can be at most:

(a) one regression line

(b) two regression lines

(c) three regression lines

(d) more regression lines

Answer:

(b) two regression lines

Question 16.

The lines of regression of X on Y estimates:

(a) X for a given value of Y

(b) Y for a given value of X

(c) X from Y and Y from X

(d) none of these

Answer:

(a) X for a given value of Y

Question 17.

Scatter diagram of the variate values (X, Y) give the idea about:

(a) functional relationship

(b) regression model

(c) distribution of errors

(d) no relation

Answer:

(a) functional relationship

Question 18.

If regression co-efficient of Y on X is 2, then the regression co-efficient of X on Y is:

(a) ≤ \(\frac{1}{2}\)

(b) 2

(c) > \(\frac{1}{2}\)

(d) 1

Answer:

(a) ≤ \(\frac{1}{2}\)

Question 19.

If two variables move in a decreasing direction then the correlation is:

(a) positive

(b) negative

(c) perfect negative

(d) no correlation

Answer:

(a) positive

Question 20.

The person suggested a mathematical method for measuring the magnitude of the linear relationship between two variables say X and Y is:

(a) Karl Pearson

(b) Spearman

(c) Croxton and Cowden

(d) Ya Lun Chou

Answer:

(a) Karl Pearson

Question 21.

The lines of regression intersect at the point:

(a) (X, Y)

(b) \((\overline{\mathrm{X}}, \overline{\mathrm{Y}})\)

(c) (0, 0)

(d) (σ_{x}, σ_{y})

Answer:

(b) \((\overline{\mathrm{X}}, \overline{\mathrm{Y}})\)

Question 22.

The term regression was introduced by:

(a) R.A Fisher

(b) Sir Francis Galton

(c) Karl Pearson

(d) Croxton and Cowden

Answer:

(b) Sir Francis Galton

Question 23.

If r = -1, then correlation between the variables:

(a) perfect positive

(b) perfect negative

(c) negative

(d) no correlation

Answer:

(b) perfect negative

Question 24.

The coefficient of correlation describes:

(a) the magnitude and direction

(b) only magnitude

(c) only direction

(d) no magnitude and no direction

Answer:

(a) the magnitude and direction

Question 25.

If Cov(x, y) = -16.5, \(\sigma_{x}^{2}\) = 2.89, \(\sigma_{y}^{2}\) = 100. Find correlation coeffient.

(a) -0.12

(b) 0.001

(c) -1

(d) -0.97

Answer:

(d) -0.97