Problem 1 This problem will present the same scenario twodifferent ways – the second one will add an additional piece ofinformation. For each scenario, you will construct an influencediagram, as indicated in the problem. (a) Imagine that a closefriend has been diagnosed with heart disease. The physicianrecommends bypass surgery. The surgery should solve the problem.When asked about the risks, the physician replies that a fewindividuals die during the operation, but most recover and thesurgery is a complete success. Thus, your friend can (most likely)anticipate a longer and healthier life after the surgery. Withoutsurgery, your friend will have a shorter and graduallydeteriorating life. Assumingthat your friend’s objective is tomaximize the quality of her life, construct an influence diagramfor this scenario.(b) Suppose now that your friend obtains a secondopinion. The second physician suggests that there is a thirdpossible outcome: Complications from surgery can develop which willrequire long and painful treatment. If this happens, the eventualoutcome can be either a full recovery, partial recovery (restrictedto a wheelchair until death) or death within a few months. Draw theinfluence diagram that represents the situation after hearing fromboth physicians. How does this change the influence diagram thatyou created in part (a)?
