Prior/Posterior Distribution

Let $\theta$ denote the proportion of registered voters in a large city who are in favour of certain proposition. Suppose that the value of $\theta$ is unknown and two statisticians A and B respectively use the following different prior distributions for $\theta$:
$h_{A}(\theta) = 2\theta, 0 < \theta < 1$
$h_{B}(\theta) = 4\theta^3, 0 < \theta < 1$
Find the posterior distribution that each statistician assignments to $\theta$ and use the means of the posterior distributions to find point estimates for each statistician.