Question

The covariance between two variables x and y is 72. The variances of x and y are 144 and 84. The
coefficient of correlation is

Answer 1

Answer:

2/3   ( 98%sure but  check my Explanation------------   it is up on you to  to decide ans thanQ )  

Explanation:

Karl Pearson Correlation Coefficient Formula

r(x,y)=cov(x,y)/σx*σy

given variances of x and y are 144 and 84  

standard deviation are of x and y are $\sqrt{144}$ =12 and$\sqrt{84}$=9.16

covariance between two variables x and y is 72

there fore

r =72 /(12*9.16)     =    0.65465   ≅  2/3

                                                     

Answer 2

Coefficient of correlation = 0.655

Explanation:

Given:

Variances of x = 144

Variances of y = 84  

Standard deviation of x = √ 144 = 12

Standard deviation of y = √ 84 = 9.16

Computation:

Covariance  x and y = 72

Correlation of Coefficient

r(x,y) = Covariance(x,y)/σx × σy

Coefficient of correlation = 72 / [12 × 9.16]

Coefficient of correlation = 72 / [109.92]

Coefficient of correlation = 0.655