Given independent random variables, X and Y, with means and standard deviations as shown, find the mean and standard deviation of each of the variables in parts a to d. a)X-12 b)0.4Y c)X+Y d)X-Y a) Find the mean and standard deviation for the random variable X - 12. E(X-12)=|:| so(x12)=D (Type integers or decimals rounded to two decimal places as needed.)