The lifetime, X, of a CPU in the Edsel computer, measured in months, has the following probability density function: f(x)= 338 x 3 for x ≥ 13 and 0 otherwise. d) What is the expected value of X...

The lifetime, X, of a CPU in the Edsel computer, measured in months, has the following probability density function:
      f(x)=

 for

 and 0 otherwise.

d) What is the expected value of X (E(X))?


e) What is the expected value of X - 7?


f) What is the expected value of 3X?