The time between calls to a plumbing supply business is exponentially distributed with a mean time between calls of 12 minutes. What is the probability that there are no calls within a 30-minute interval? 0.0821 (Round your answer to 4 decimal places.) What is the probability that at least one call arrives within a 10-minute interval? 0.5654 (Round your answer to 4 decimal places.) What is the probability that the first call arrives within 5 and 10 minutes after opening? 0.2246 (Round your answer to 4 decimal places.) Determine the length of an interval of time such that the probability of at least one call in the interval is 0.90. 69.64 minutes (Round your answer to 2 decimal places.)
