The coefficient of correlation between two variables x and y is 0.5. Their covariance is 16 and standard deviation of x is 4. Then the standard deviation of y is
4
8
16
64
If cov(x,y)= -1.55, var (x) = 1.55, var (y)= 1.55, then ρ(x,y) =
1
- 1
0
2
If y = px+3 and x = 3y+5 are the regression lines of y on x and x on y respectively, then
0 ≤ p≤1/3
0 ≤ p ≤1/5
0 ≤ p ≤ 1/15
0 ≤ p ≤ 5
If Spearman's co-efficient of rank correlation is equal to one then:
The ranking of the two variables totally agree
All the total variation is explained by the regression line
The ranking of the two variables is totally different
The ranking of the two variables partially agree
If Ui = axi +b and Vi = yi+d and γxy = 0.8 then γuv =
0.8a
0.4
0.4/a
0.8
The coefficient of correlation between x and y is 0.6. Their covariance is 4.8 and var(x)= 9 . Then σy =
3/8
8/3
8/9
9/8
