# Bernoulli random variable problem

## Homework Statement

Suppose we want to estimate a binomial proportion, p. We take a sample of size n and count X successes.

Consider a Bernoulli random variable, Y that is 1 with probability p and 0 otherwise. Show that the mean and variance of Y are p and p(1-p), respectively.

## The Attempt at a Solution

Not too sure what to do here. I know that the mean is calculated by $$\Sigma$$xf(x) and variance is E(X-mean)2

rock.freak667
Homework Helper

## The Attempt at a Solution

Not too sure what to do here. I know that the mean is calculated by $$\Sigma$$xf(x) and variance is E(X-mean)2

Well write out your sample space

y 0 1
P(Y=y)