Digicom is a computer business that is evaluating the installation of computer terminals at a conference centre where the Michigan Association of Disgruntled Students (MADS) is going to hold its annual convention. Assume there will be one single queue to access all the computer terminals and that only one person uses a computer at a time. Digicom estimates that there will be 4 arrivals per minute on average to the computer terminals, with a standard deviation of the time between arrivals of 15 seconds. The average time a person spends using a terminal is 4 minutes with standard deviation of 2 minutes. Suppose Digicom installs 20 terminals. On average, how many of the terminals will be available when a disgruntled studies shows up to use a computer?