The Average Number of Calls Received by a Switchboard in a 30-Minute

question 89

Short Answer

The average number of calls received by a switchboard in a 30-minute period is 15.
a.What is the probability that between 10:00 and 10:30 the switchboard will receive exactly 10 calls?
b.What is the probability that between 10:00 and 10:30 the switchboard will receive more than 9 calls but fewer than 15 calls?
c.What is the probability that between 10:00 and 10:30 the switchboard will receive fewer than 7 calls?

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Definitions:

Dividend

A portion of a company's earnings distributed to shareholders, often in the form of cash or additional shares.

Variance

A statistical measure that represents the average squared deviation from the mean, used to indicate the spread of a set of data points.

Returns

The profit or loss generated on an investment over a particular period, typically expressed as a percentage of the investment's initial cost.

Annual Coupon Bond

A bond that pays interest to the holder annually until its maturity, at which point the principal is repaid.