On average 2 customers per hour use the public telephone in the sheriff's detention area, and this use has a Poisson distribution. The length of the phone call follows exponential distribution with a mean of 6 minutes. The sheriff will install a second telephone booth when an arrival can expect to wait 3 minutes or longer for the phone. What is the arrival rate that justifies a second telephone booth?

Aldrich and co. sold goods to donovan on credit. the amount owed grew steadily, and finally aldrich refused to sell any more to donovan unless donovan signed a promissory note for the amount due. donovan did not want to but signed the note because he had no money and needed more goods. when aldrich brought an action to enforce the note, donovan claimed that the note was not binding because it had been obtained by economic duress. was he correct? [aldrich & co. v. donovan, 778 p.2d 397 (mont.)]

Eliza works for a consumer agency educating young people about advertisements. instead of teaching students to carefully read advertisement claims, she encourages them to develop a strong sense of self and to keep their life goals and dreams separate from commercial products. why might eliza's advice make sense?

Quick computing currently sells 12 million computer chips each year at a price of $19 per chip. it is about to introduce a new chip, and it forecasts annual sales of 22 million of these improved chips at a price of $24 each. however, demand for the old chip will decrease, and sales of the old chip are expected to fall to 6 million per year. the old chips cost $10 each to manufacture, and the new ones will cost $14 each. what is the proper cash flow to use to evaluate the present value of the introduction of the new chip? (enter your answer in millions.)