(10 points) A statistical software consultant is hired to answer a company's help line. Let A be the event that the next caller will call with a question about SAS and let B be the event that the next caller will call with a question about R. (a) Does P(A) + P(B) =1? Why or why not? (3 points) (b) Calculate P( A'). (2 points) (c) Calculate P(AU B). (2 points) (d) Calculate P(A'n B'). (2 points)