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In the customer-arrival example, time between customers is exponential with a mean of:
ATwenty minutes
BSixty minutes
CTwo minutes
DTen minutes
Answer & Solution
Correct answer: C. Two minutes
1. The worked example fixes a specific mean waiting time.
2. The amount of time between customers is exponentially distributed.
3. It has a mean of two minutes, written X ~ Exp(0.5).
4. That example is used to illustrate memorylessness.
_Source: OpenStax Introductory Statistics 2e (CC BY 4.0), Ch 5 'Continuous Random Variables', sections 5.1-5.3_
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