Answer Happy

Bayesian analysis part 1 A certain person buys a houseplant. She buys either a cactus or an orchid. From long experience I can say that it is a cactus with probability 0.4, or an orchid with probability 0.6. She then goes on holiday and does not water her plants. The plants get too dry and might die. Under these circumstances, a cactus will die with probability 0.05 and an orchid with probability 0.24. The plant dies. Apply Bayes's theorem and show your working. What is the posterior probability that it was a cactus? Excellence question: consider the probability of the plant being a cactus. Discuss how this probability changes from prior to posterior in the light of your observation and whether this is consistent with your intuition.