help me with this problem
(i) What is the probability that there are no calls within a 30 minute interval?
- The time between calls to a plumbing supply business is exponentially distributed with a mean time between calls of 15 minutes.
(ii) What is the probability that at least one call arrives within a 10 minute interval?
(iii) What is the probability that the first call arrives within 5 and 10 minutes after opening?
(iv) Determine the length of an interval of time such that the probability of at least one call in the interval is 0.90.
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