## Given the Variance of a Bernoulli Random Variable, Find Its Expectation

## Problem 748

Suppose that $X$ is a random variable with Bernoulli distribution $B_p$ with probability parameter $p$.

Assume that the variance $V(X) = 0.21$. We further assume that $p > 0.5$.

**(a)** Find the probability $p$.

**(b)** Find the expectation $E(X)$.