You may need to use the appropriate appendix table or technology to answer this question. The average number of calls received by a switchboard in a 30 minute period is 15. (Round your answers to four decimal places.) (a) What is the probability that between 10:00 and 10:30 the switchboard will receive exactly 12 calls? (b) What is the probability that between 10:00 and 10:30 the switchboard will receive more than 9 calls but fewer than 17 calls? (c) What is the probability that between 10:00 and 10:30 the switchboard will receive fewer than 10 calls? You may need to use the appropriate appendix table or technology to answer this question. The average number of calls received by a switchboard in a 30 minute period is 15. (Round your answers to four decimal places.) (a) What is the probability that between 10:00 and 10:30 the switchboard will receive exactly 12 calls? (b) What is the probability that between 10:00 and 10:30 the switchboard will receive more than 9 calls but fewer than 17 calls? (c) What is the probability that between 10:00 and 10:30 the switchboard will receive fewer than 10 calls