chapter 1

Chapter 2: Probability14.a. P(A ∪ B) = P(A) + P(B) - P(A ∩ B),so P(A ∩ B) = P(A) + P(B) - P(A ∪ B)= .8 +.7 - .9 = .6b. P(shaded region) = P(A ∪ B) - P(A ∩ B) = .9 - .6 = .3Shaded region = event of interest = (A ∩ B′) ∪ (A′ ∩ B)15.a. Let event E be the event that at most one purchases an electric dryer. Then E′ is the eventthat at least two purchase electric dryers.P(E′) = 1 – P(E) = 1 - .428 = .572b. Let event A be the event that all five purchase gas. Let event B be the event that all fivepurchase electric. All other possible outcomes are those in which at least one of eachtype is purchased. Thus, the desired probability =1 – P(A) – P(B) = 1 - .116 - .005 = .87916.a. There are six simple events, corresponding to the outcomes CDP, CPD, DCP, DPC, PCD,and PDC. The probability assigned to each is 6 1 .b. P( C ranked first) = P( {CPD, CDP} ) = 1 1 2+ = = . 333c. P( C ranked first and D last) = P({CPD}) = 6166656