Given that the arithmetic mean and standard deviation of a sample of 15 observations are 24 and 0 respectively. Then which one of the following is the arithmetic mean of the smallest five observations in the data?

Which one of the following can be considered as appropriate pair of values of regression coefficient of y on x and regression coefficient of x on y ?

It is given that $$\overline X = 10$$, $$\overline Y = 90$$, $${\sigma _X} = 3$$, $${\sigma _Y} = 12$$ and $${r_{XY}} = 0.8$$. The regression equation of X on Y is

If a variable takes values 0, 1, 2, 3, ......., n with frequencies 1, C(n, 1), C(n, 2), C(n, 3), ......., C(n, n) respectively, then the arithmetic mean is