Second moment and variance of an exponential waiting time

E(T^2) = 2 tau^2 and Var(T) = tau^2.

Usage

ExpMom2(tau)

Arguments

tau

mean waiting time, > 0.

Value

list(second_moment, variance).

References

Morin, D. J. (2016). Probability: For the Enthusiastic Beginner. Createspace. Eq (4.85).

Examples

ExpMom2(2.5)$variance
#> [1] 6.25