A new phone answering system for a company is capable of handeling seven calls every 10 minutes. Prior to installing the new system, company analyst determined that the incoming calls to the system are Poisson distributed with a mean of four every 10 minutes. If this incoming call distribution is what the analysts thinks it is, what is the probability in a 10 minute period more calls will arrive than the system can handle?
The probability that more calls will arrive than the system can handle is ( )