You bought a stock on 1 January 2018 for $35.5 and below are the year-end price data and annual dividends for the stock: Date Closing Price Annual Dividend 31 December 2017 35.5 0.6 31 December 2018 38.2 0.65 31 December 2019 36.8 0.5 31 December 2020 40.7 0.7 What is the standard deviation of returns on this stock over the 2018-2020 period? O 0.0821 0.0062 0 0.0784 O 0.0067 O 0.0640 Suppose you create a portfolio with two securities: Security Security Weight (%) Security Variance (%) 70 20 Y 30 24 If the correlation coefficient between the two securities is 0.5, what is the standard deviation of the portfolio? 0.1867 0.4070 0.3901 0.1656 O 0.0349