You have a portfolio that is allocated $50\%$ to META, $30\%$ to TSLA and $20\%$ to AMZN. Given the following returns under the following states of the economy, what's the standard deviation of the portfolio?

IN EXCEL

Rate of return if state occurs

State of economy Probability of state occurring META TSLA AMZN

Growth $8\%15\mathrm{.}00\%16\mathrm{.}00\%17\mathrm{.}00\%$

Stagnant $92\%8\mathrm{.}00\%9\mathrm{.}00\%10\mathrm{.}00\%$