Construct a decision tree and determine the optimum decision for an engineer in business for himself. The potential losses involved are small compared to his working capital. The engineer either may accept the beam design his employee has selected and shown on the plans or he may ask for a revision in the design involving a drafting cost of $100. There is no gain or loss associated with a design which performs satisfactorily. If, however, the long-term creep deflection of the concrete beam is excessive, the engineer estimates a (discounted) future loss of $500 in potential fees and inconvenience to his client (as the client's losses are reflected through professional responsibility in dollar loss to the engineer). The sustained loads are quite well known for this structural type, but uncertainty exists in the long-term effective modulus of elasticity of a reinforced-concrete beam. The engineer is concerned because the likelihood of this modulus being greater than 4000 ksi, i.e., the value needed for satisfactory performance of the present design, is only 0.3. With redesign a value of the modulus of 3000 ksi would be satisfactory. This value will be exceeded, the engineer feels, with odds 3 in 4.