Finding the expectation of n Poisson values in R

Question

I have written the following code:

n <- 5
lambda <- 2
randomNumbers <- rpois(n, lambda)
prob <- dpois(randomNumbers, lambda)

Is my code correct thus far?

How can I find the expected values of 5 Poisson values?

eX <- mean(randomNumbers)

or,

weighted.mean(randomNumbers, prob)

Answer 1

n <- 5
lambda <- 2
randomNumbers <- rpois(n, lambda)
# estimate of P(X = 0), for example
mean(randomNumbers == 0)
# estimate of E[X]
mean(randomNumbers)