Poisson Distribution
Introduction
TBA
Density function
The density function for the Poisson distribution is
The density function for the Poisson distribution depends on the rate parameter .
Specific to the plot above, the density function is
Examples
- A seismologist has been studying the frequency of small earthquakes in a
particular geologically active region. Over the course of several years,
she determines that on average, there are 3.5 small earthquakes per day in
this region.
- What is the probability that on a given day there are exactly 2 earthquakes?
- What is the probability that on a given day there are 3 or more earthquakes?
- Over the course of a week (7 days), what's the probability that there is at most 5 earthquakes?
- You are a future math teacher preparing lesson plans on the Poisson
distribution. You decide to use real-world data from the school library's
study room booking system as a teaching tool. Records from the library
indicate that, on average, 5 students request to book a study room every
hour. Assuming that the number of booking requests follows a Poisson
distribution:
- What is the probability that exactly 7 students will request to book a study room in a given hour?
- What is the probability that 3 or fewer students will request to book a study room in a given hour?
- During a two-hour span, what is the probability that more than 10 students will request to book a study room?
- Consider a busy intersection in a city. Past data has shown that, on
average, 5 vehicles per hour make a wrong turn at this intersection due to
a lack of clear signage.
- What is the probability that exactly 3 vehicles will make a wrong turn in the next hour?
- What is the probability that no vehicles will make a wrong turn in the next hour?
- If the city's engineering department plans to monitor the intersection for a 4-hour period, what is the probability that more than 20 vehicles will make a wrong turn during this time?
- In a chemical processing plant, a specific reactor is known to have a rare
malfunction due to random impurities in the reactants. Over the past
several years, data has shown that this malfunction occurs on average 1.5
times every 100 hours of operation. A new batch of reactant is being
processed in this reactor for a continuous 48-hour run.
- What is the probability that there will be no malfunctions during this 48-hour run?
- What is the probability that there will be at least one malfunction during this 48-hour run?
- What is the probability that there will be more than two malfunctions during this 48-hour run?
Calculator
Poisson( ). .
References
Poisson distribution. Wikipedia: The Free Encyclopedia. Wikimedia Foundation, Inc. Accessed 06/10/2023.
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