# Statistics

The amount of time a bank teller spends with each customer has a population mean µ = 3.10 minutes and a standard deviation σ = 0.60. If a random sample of 36 customers is selected,

a. What is the probability that the average time will be at least 3 minutes?

b. What is the probability the average time will be between 3.05 and 3.2 minutes?

Please use the attachments provided and not only excel functions.

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#### Solution Preview

M = 3.1, SD = 0.60, n = 36

(a) z = (x - M)/(SD/sqrt n)

z = (3 - 3.1)/(0.60/sqrt 36) = ...

#### Solution Summary

Neat solution is provided to the problem.

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