Distributions X and Y have the same coefficients of variation. If the mean of X is twice the mean of Y and the standard deviation of X is 5, the standard deviation of
Y is ________.
Click on the arrows to vote for the correct answer
A. B. C. D.C
coefficient of variation = standard deviation/mean. If the mean of Y is M, then the coefficient of variation of X is 5/(2M) and that of Y is (standard deviation of Y)/M.
Given that these two are equal, 5/(2M) = (standard deviation of Y)/M. Therefore, standard deviation of Y = 5/2 = 2.5.