If the covariance between x and y is 30, variance of x is 25 and variance of y is 144, then what is the correlation coefficient?

Options

A. `0.4`
B. `0.5`
C. `0.6`
D. `0.7`

Answer

B

Explanation

`cov(x,y)=30`
`var(x)=25, var(y)=144`
`rArr r(x,y)=(cov(x,y))/(sqrt(var(x).var(y)))`
`rArr r(x,y)=(30)/(sqrt(25xx144))=(30)/(5xx12)=0.5`