Advertisements
Advertisements
प्रश्न
Bring out the inconsistency, if any in the following :
bYX = 1.9 and bXY = -0.25
उत्तर
byx = 1.9 and bxy = -0.25
Since both the regression coefficient must have same sign .
∴ data is inconsistent.
APPEARS IN
संबंधित प्रश्न
Examine whether the following statement pattern is tautology, contradiction or contingency :
p ∨ – (p ∧ q)
Bring out the inconsistency; if any: byx + bxy = 1.30. and r = 0.75
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 mean marks in accountancy is 44 and the variance of marks in statistics is `(9/16)^(th)` of the variance of marks in accountancy. Find the mean marks in statistics and the correlation coefficient between marks in the two subjects.
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 two regression equations y = 4x - 5 and 3x = 2y + 5, find `barx and bary`
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.
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.
By using the data `bar"x"` = 25 , `bar"y" = 30 ; "b"_"yx" = 1.6` and `"b"_"xy" = 0.4` find,
(a) The regression equation y on x.
(b) What is the most likely value of y when x = 60?
(c) What is the coefficient of correlation between x and y?
Find the line of best fit for the following data, treating x as the dependent variable (Regression equation x on y):
X | 14 | 12 | 13 | 14 | 16 | 10 | 13 | 12 |
Y | 14 | 23 | 17 | 24 | 18 | 25 | 23 | 24 |
Hence, estimate the value of x when y = 16.
A psychologist selected a random sample of 22 students. He grouped them in 11 pairs so that the students in each pair have nearly equal scores in an intelligence test. In each pair, one student was taught by method A and the other by method B and examined after the course. The marks obtained by them after the course are as follows:
Pairs | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
Methods A | 24 | 29 | 19 | 14 | 30 | 19 | 27 | 30 | 20 | 28 | 11 |
Methods B | 37 | 35 | 16 | 26 | 23 | 27 | 19 | 20 | 16 | 11 | 21 |
Calculate Spearman’s Rank correlation.
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)
The marks obtained by 10 candidates in English and Mathematics are given below:
Marks in English | 20 | 13 | 18 | 21 | 11 | 12 | 17 | 14 | 19 | 15 |
Marks in Mathematics | 17 | 12 | 23 | 25 | 14 | 8 | 19 | 21 | 22 | 19 |
Estimate the probable score for Mathematics if the marks obtained in English are 24.
If the regression line of x on y is, 9x + 3y − 46 = 0 and y on x is, 3x + 12y − 7 = 0, then the correlation coefficient ‘r’ is equal to:
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 ______.
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?
The random variables have regression lines 3x + 2y − 26 = 0 and 6x + y − 31 = 0. Calculate co-efficient of correlations.