HSC Commerce: Marketing and Salesmanship १२ वीं कक्षा - Maharashtra State Board Question Bank Solutions

State whether the following statement is True or False: 

If b_xy < 0 and b_yx < 0 then ‘r’ is > 0

The following data is not consistent: b_yx + b_xy =1.3 and r = 0.75

State whether the following statement is True or False: 

If u = x – a and v = y – b then b_xy = b_uv 

State whether the following statement is True or False:

Corr(x, x) = 0

Corr(x, x) = 1

State whether the following statement is True or False:

Cov(x, x) = Variance of x

State whether the following statement is True or False:

Regression coefficient of x on y is the slope of regression line of x on y

If n = 5, ∑xy = 76, ∑x² = ∑y² = 90, ∑x = 20 = ∑y, the covariance = ______

|b_xy + b_yx| ≥ ______

If u = `(x - "a")/"c"` and v = `(y - "b")/"d"`, then b_xy = ______ 

If the sign of the correlation coefficient is negative, then the sign of the slope of the respective regression line is ______

The value of product moment correlation coefficient between x and x is ______

Arithmetic mean of positive values of regression coefficients is greater than or equal to ______

If u = `(x - 20)/5` and v = `(y - 30)/4`, then b_yx = ______

The geometric mean of negative regression coefficients is ______

b_yx is the ______ of regression line of y on x

The equations of two lines of regression are 3x + 2y – 26 = 0 and 6x + y – 31 = 0. Find variance of x if variance of y is 36

Given the following information about the production and demand of a commodity.
Obtain the two regression lines:

Coefficient of correlation between x and y is 0.8.
What should be the advertising budget if the company wants to attain the sales target of ₹ 150 lakhs?

The equations of the two lines of regression are 2x + 3y − 6 = 0 and 5x + 7y − 12 = 0. Find the value of the correlation coefficient `("Given"  sqrt(0.933) = 0.9667)`

Given the following information about the production and demand of a commodity.

Obtain the two regression lines:

Coefficient of correlation between X and Y is 0.6. Also estimate the demand when the production is 100 units.