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If bYX = − 0.6 and bXY = − 0.216, then find correlation coefficient between X and Y. Comment on it.

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प्रश्न

If bYX = − 0.6 and bXY = − 0.216, then find correlation coefficient between X and Y. Comment on it.

योग
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उत्तर

Given, bYX = − 0.6, bXY = − 0.216

∴ r = `+-sqrt("b"_"XY" * "b"_"YX")`

`= +- sqrt(- 0.216 * (- 0.6)) = +- sqrt(0.1296)`

∴ r = ± 0.36

Since bXY and bYX are negative,

r is also negative.

∴ r = - 0.36

∴ X and Y negatively correlated.

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Properties of Regression Coefficients
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 3: Linear Regression - Miscellaneous Exercise 3 [पृष्ठ ५४]

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बालभारती Mathematics and Statistics 2 (Commerce) [English] Standard 12 Maharashtra State Board
अध्याय 3 Linear Regression
Miscellaneous Exercise 3 | Q 4.12 | पृष्ठ ५४

संबंधित प्रश्न

From the data of 7 pairs of observations on X and Y, following results are obtained.

∑(xi - 70) = - 35,  ∑(yi - 60) = - 7,

∑(xi - 70)2 = 2989,    ∑(yi - 60)2 = 476, 

∑(xi - 70)(yi - 60) = 1064

[Given: `sqrt0.7884` = 0.8879]

Obtain

  1. The line of regression of Y on X.
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  3. The correlation coefficient between X and Y.

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bYX = 1.9 and bXY = - 0.25


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Variance of X = 9
Regression equations:
8x − 10y + 66 = 0
and 40x − 18y = 214.
Find on the basis of above information

  1. The mean values of X and Y.
  2. Correlation coefficient between X and Y.
  3. Standard deviation of Y.

For 50 students of a class, the regression equation of marks in statistics (X) on the marks in accountancy (Y) is 3y − 5x + 180 = 0.  The variance of marks in statistics is `(9/16)^"th"` of the variance of marks in accountancy. Find the correlation coefficient between marks in two subjects.


For bivariate data, the regression coefficient of Y on X is 0.4 and the regression coefficient of X on Y is 0.9. Find the value of the variance of Y if the variance of X is 9.


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and 3x + 2y − 12 = 0 Find 

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  3. Coefficient of correlation between X and Y.

If the two regression lines for a bivariate data are 2x = y + 15 (x on y) and 4y = 3x + 25 (y on x), find

  1. `bar x`,
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Choose the correct alternative:

If r = 0.5, σx = 3, `σ_"y"^2` = 16, then byx = ______


Choose the correct alternative:

If r = 0.5, σx = 3, σy2 = 16, then bxy = ______


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If bxy < 0 and byx < 0 then ‘r’ is > 0


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Cov(x, x) = Variance of x


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


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Mean of x = 53

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∴ y = `square`

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∴ x = `square`


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∴ byx = `square/square`

∴ r = `square`


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