A Xerox copier is making only faintcopies (event F). The office manager needs to determine thecause of this. In general, copiers may have electricalproblems (E), mechanical problems (M), user problems (U), or noproblems (N). If a problem is E or M, an expensive technicianis called. If a problem is U, then Rhonda fixes it, but sheis on vacation until tomorrow. The manager must determinePr(U|F).
The copier warranty indicates thatPr(E) = 0.02, Pr(M) = 0.05, and Pr(U) = 0.15. The manual says faint copies accompany electrical problems 8% of the time,mechanical problems 6% of the time, and user problems 86%: Pr(F|E) = 0.08, Pr(F|M) = 0.06, Pr(F|U) = 0.86, and Pr(F|N) =0.
You're the manager. What do you do, and why?