CORRELATION COEFFICIENT For XI

           BIVERTIA DATA

             

1) Correlation between x and y is 0.52, their covariance is 7.8. If the variance of x is 16, then S.D of y is:

2) Find r if ∑x=50, ∑y=100, ∑x²=25, ∑y²=45, ∑xy=630,n=10

3) Find r if  ∑x=125, ∑y=100,

∑x²= 650, ∑y²=436, ∑xy=520,n=25

4) Find r if
¹²ᵢ₌₁∑(x - mean of x)²=120,
  ¹²ᵢ₌₁∑(y- mean of y)²=250 ,
 ¹²ᵢ₌₁∑(x-mean of x)(y-mn of y)
                                              =225.

5) If cov(x,y)=12, r=0.6 and s.d of
    x=5 find s.d of y.

6) If r=0.5, ∑xy=120,∑x²=90 and s.d
     of y=8 find n

7) cov(u,v)=3, variance of u= 4.5, variance of v=5.5, fund r.

8) Find the probable error of r if
      r=0.05 and n=25.

9) If r=0.526 and n=50, what is the probable of r.

10) ¹⁰⁰ᵢ₌₁∑x=280, ¹⁰⁰ᵢ₌₁∑y=60,

     ¹⁰⁰ᵢ₌₁∑x²=2384, ¹⁰⁰ᵢ₌₁∑y²=117,

     ¹⁰⁰ᵢ₌₁∑xy=438. find

Find Karl Pearson'sCorrelation coefficient

11) X: 1  2    3   4    5

 .     Y: 3  2    5.  4     6 find r.

12) X: 1    2   3    4    5

       Y: 6    8  11   8    12    Find r.

13) X: 10  12 13 16 17  20 25

       Y: 19  22 24 27  29 33 37

      Find r.

14) Find r taking 44 and 26 as the  

     origin of X and Y

X: 43 44 46 40 44 42 45 42 38 40

Y: 28 31 19 18 19 27 27 29 41 30

15) In order to find the correlation coefficient between X and Y where n=12, ∑x=30, ∑y=5, ∑x²=670, y²=285, xy=334. On subsequent verification it was found that the pair (11,4) was copied wrongly, the correct value being(10,14). find correct correlation coefficient.

16) In order to find the correlation coefficient between X and Y where n=25, ∑x=125, ∑y=100, ∑x²=650, y²=460, xy= 508. On subsequent verification it was found that (6,14) and (8,6) was copied wrongly, the correct value being(8,12) and (6,8). find correct correlation coefficient.