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:

Drum Brakes

A type of braking system using brake shoes pressed outward against a rotating drum to slow or stop a vehicle.

Disc Brakes

A type of brake that slows or stops a vehicle by squeezing brake pads against a disc or rotor attached to the wheel.

Brake Fade

A reduction in the braking power of a vehicle, often due to overheating of the brake components during heavy use.

Water Fade

A decrease in the performance of brake components due to the presence of water.