Advertisements
Advertisements
प्रश्न
Values of two regression coefficients between the variables X and Y are `b_"yx" = - 0.4` and `b_"xy"` = - 2.025 respectively. Obtain the value of correlation coefficient.
उत्तर
Correlation coefficient is
`r = ±sqrt(b_"yx".b_"xy")`
`r = ±sqrt(-2.025 xx - 0.4)`
`r = ±sqrt(0.81)`
⇒ r = -0.9 (∵ `b_"yx" and b_"xy"` are negative)
APPEARS IN
संबंधित प्रश्न
The two lines of regressions are 4x + 2y- 3 = 0 and 3x + 6y + 5 =0. Find the correlation co-efficient between x and y.
In a contest, the competitors are awarded marks out of 20 by two judges. The scores of the 10 competitors are given below. Calculate Spearman's rank correlation.
| Competitors | A | B | C | D | E | F | G | H | I | J |
| Judge A | 2 | 11 | 11 | 18 | 6 | 5 | 8 | 16 | 13 | 15 |
| Judge B | 6 | 11 | 16 | 9 | 14 | 20 | 4 | 3 | 13 | 17 |
Examine whether the following statement pattern is tautology, contradiction or contingency :
p ∨ – (p ∧ q)
The regression equation of y on x is given by 3x + 2y - 26 = O. Find byx.
For a bivariate data,
`bar x = 53 , bar y = 28 , "b"_"xy" = -1.5 and "b"_"xy"=- 0.2` Find
Correlation coefficient between X and Y
For a bivariate data,
`bar x = 53 , bar y = 28 , "b"_"xy" = - 0.2` , `"b"_"yx" = -1.5` Find
Estimate of Y , When X = 50.
From the data 7 pairs of observations on X and Y following results are obtained :
∑(xi - 70) = - 38 ; ∑ (yi - 60) = - 5 ;
∑ (xi - 70)2 = 2990 ; ∑ (yi - 60)2 = 475 ;
∑ (xi - 70) (yi - 60) = 1063
Obtain :
(a) The line of regression of Y on X.
(b) The line of regression of X on Y.
Let X be the number of matches played by the player and Y he the number of matches in which he scored more thun 50 runs. The following data is obtained for 5 players :
| No. of Matches Played (X) | Data of matches of 5 players | ||||
| 21 | 25 | 26 | 24 | 19 | |
| Scored more than 50 in a match (Y) | 19 | 20 | 24 | 21 | 16 |
Find the regression line of X on Y.
Calculate Karl Pearson’s coefficient of correlation between x and y for the following data and interpret the result:
(1, 6), (2, 5), (3, 7), (4, 9), (5, 8), (6, 10), (7, 11), (8, 13), (9, 12)
For 5 observations of pairs (x, y) of variables X and Y, the following results are obtained:
∑x = 15, ∑y = 25, ∑x2 = 55, ∑y2 = 135, ∑xy = 83.
Calculate the value of bxy and byx.
If the two regression coefficients are 0.8 and 0.2, then the value of coefficient of correlation r will be ______.
The following table shows the Mean, the Standard Deviation and the coefficient of correlation of two variables x and y.
| Series | x | y |
| Mean | 8 | 6 |
| Standard deviation | 12 | 4 |
| Coefficient of correlation | 0.6 | |
Calculate:
- the regression coefficient bxy and byx
- the probable value of y when x = 20
If the correlation coefficient of two sets of variables (X, Y) is `(-3)/4`, which one of the following statements is true for the same set of variables?
Mean of x = 53, mean of y = 28 regression co-efficient y on x = −1.2, regression co-efficient x on y = −0.3. Find coefficient of correlation (r).
The random variables have regression lines 3x + 2y − 26 = 0 and 6x + y − 31 = 0. Calculate co-efficient of correlations.
