Poisson distribution notation

The binomial distribution notation is to write X\sim B(n, p). This means:

The notation for a poisson distribution is very similar. We can write X\sim P(\lambda), which means:

X is a discrete random variable
X follows a poisson distribution - shown by the P
\lambda is the mean number of successes in the given time period (or area, etc.)

This isn’t so common though, because the P may be confused with a probability. to get around that, we usually write Po instead of P:

X\sim Po(\lambda)

flashcards

Question	Answer
X\sim B(n, p)	X is a discrete random variable, X follows a binomial distribution, n is the number of trials, and p is the probability of success on each trial.
X\sim P(\lambda)	X is a discrete random variable, X follows a Poisson distribution, and \lambda is the mean number of successes in the given time period (or area, etc.).
Why is P not commonly used for Poisson distribution notation?	The P may be confused with a probability, so Po is usually written instead.