Find E(x), E(x2), the mean, the variance, and the standard deviation of the random variable whose probability density function is given below. f ( x) = 1800 x, [0,60] . . . . . E(x ) (Type an integer or a simplified fraction.) E(x2) = (Type an integer or a simplified fraction.). . . . . E(x) = (Type an integer or a simplified fraction.) E(x2) = (Type an integer or a simplified fraction.) H= (Type an integer or a simplified fraction.) 62 = (Type an integer or a simplified fraction.)