A project manager has compiled a list of major activities that will be required to install a computer information system in her company. The list includes 3-point estimates of durations (optimistic, most likely, pessimistic) for activities and the precedence relationships.

If the project is finished within 26 weeks of its start, the project manager will receive a bonus of $1.000: and if the project is finished within 27 weeks of its start, the bonus will be $500. Find the probability of each bonus.