Afirm pays its accountant an annual retainer of $10 000. is this an economic cost

Alyssa works for an engineering firm that has been hired to design and supervise the construction of a highway bridge over a major river. the bridge will be a unique design, incorporating complex designs that will likely never be duplicated. how should alyssa deal with designing and overseeing the building of the bridge?

Anew 2-lane road is needed in a part of town that is growing. at some point the road will need 4 lanes to handle the anticipated traffic. if the city's optimistic estimate of growth is used, the expansion will be needed in 4 years and has a probability of happening of 40%. for the most likely and pessimistic estimates, the expansion will be needed in 8 and 15 years respectively. the probability of the pessimistic estimate happening is 20%. the expansion will cost $ 4.2 million and the interest rate is 8%. what is the expected pw the expansion will cost?

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends > a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?