e). The film was nearing an end and suddenly I heard 4 knocks, sound heard when somebody knocks onto the wood. The first thought that came to my mind was '"Did a ghost just knock on my window?". For a brief moment I got entangled in a state of indecisiveness and then my curiousity of seeing a ghost took me over. Looking through my window saw nothing else but stillness of the night against a flickering tube competing with the moon.The marginal benefit of seeing a ghost would indeed be greater than the marginal cost involved in going sleepless through more than half the night.
