# How to calculate the variance

So i have this question and I wanted to be sure that my calculations were correct.

The standard deviations of the market returns is $$0.2(20%)$$ and the covariance between the return on the market portfolio and Amazon is $$0.05$$. Calculate the beta of Amazon.

So i know that Beta= (covariance)/ variance, where

• Covariance=Measure of a stock’s return relative to that of the market,
• Variance=Measure of how the market moves relative to its mean.

Then am I correct by squaring the Standard deviation of the market returns ($$0.2$$ times $$0.2$$) to get $$0.04$$ as the variance and then the Beta would be $$0.05/0.04$$?