You are given the following data relating to a frequency distribution of 10 observations: $\displaystyle \Sigma X = 50, \Sigma Y = 60, \Sigma X^2 = 300, \Sigma Y^2 = 352, \Sigma(X + Y)^2 = 1372$ then Cov(X, Y) is

The coefficient of rank correlation in a beauty contest of 10 candidates by two judges A & B was found to be 0.5. If it was later discovered that the difference in rank of one candidate was wrongly taken as 3 instead of 7. The corrected coefficient of rank correlation is?

The coefficient of correlation between x and y is 0.6. If u & v variables are defined as $\displaystyle 2u+x-3=0$ and $\displaystyle 3v+y-2=0$ then the coefficient of correlation between u & v is?

If the plotted points in a scatter diagram are evenly distributed, then the correlation is

Speed of an automobile and the distance required to stop the car after applying brakes correlation is

A relationship $\displaystyle r^2 = 1 - \frac{500}{300}$ is not possible

If the plotted points in a scatter diagram lie from upper left to lower right, then correlation is