A company is studying the feasibility of buying an elevator for a building under construction. One proposal is a 10-passenger elevator that, on average, would arrive in the lobby once per minute. The company rejects this proposal because it expects and average of five passengers per minute to use the elevator. Aupport the proposal by calculating the probability that in any given minute, the elevator does not show up, and 10 or more passengers arrive. Determine the probability that the elevator arrives only once in a five-minute period.