January 28, 2011
Out of a group of 100 patients being treated for chronic back trouble, 25% are chosen at random to receive a new, experimental treatment as opposed to the more usual muscle relaxant-based therapy which the remaining patients receive. Preliminary studies suggest that the probability of a cure with the standard treatment is 0.3, while the probability of a cure from the new treatment is 0.6. Sometime later, one of the patients returns to thank the staff for her complete recovery.
â€What is the probability that she was given the new treatment?â€