A friend who lives in Los Angeles makes

Chapter 2, Problem 68

(choose chapter or problem)

A friend who lives in Los Angeles makes frequent consultingtrips to Washington, D.C.; 50% of the time shetravels on airline #1, 30% of the time on airline #2, andthe remaining 20% of the time on airline #3. For airline#1, flights are late into D.C. 30% of the time and late intoL.A. 10% of the time. For airline #2, these percentagesare 25% and 20%, whereas for airline #3 the percentagesare 40% and 25%. If we learn that on a particular trip shearrived late at exactly one of the two destinations, whatare the posterior probabilities of having flown on airlines#1, #2, and #3? Assume that the chance of a late arrival inL.A. is unaffected by what happens on the flight to D.C.[Hint: From the tip of each first-generation branch on atree diagram, draw three second-generation brancheslabeled, respectively, 0 late, 1 late, and 2 late.]