I need help with standard deviation for company A nad Company B

the average annual return on the equally-weighted portfolio and the standard deviation for that period

calculate the correlation coefficient

this the data for the question above

The followng table, contains annual returns for the stocks of Company A(A) and Company B (B) The returns are calculated using end-of-yoar prices (adjusted for dividends and stock splits) retrieved from http://www.finance.yahoo.com/. Use Excet to create a spreadsheet that calculates the return that a equally-weighted porttolio of these two stocks would have earned in each year. Then, calculate the average return and standard deviation for each stock ove this period Next, the average return and standard deviation for a porttolio that invests 50% in A and 50% in B. What is the correlation between A and B returns over this peniod? The average annual return tor Company A over this period is \%. (Enter as a percentage and round to two decimal places) The average annual return for Company B over this penod is \% (Enter as a percentage and round to two decimal places) The standard deviation for Company A over this period is 6. (Enter as a percentage and found to two decimal places) \begin{tabular}{|l|l|l|l|} \hline \multicolumn{2}{|c|}{ A B } & \multicolumn{1}{|c|}{ B } \\ \hline & Year & A Returns & B Returns \\ \hline 2 & 2005 & 4.2% & 17.8% \\ \hline 3 & 2006 & 2.2% & 6.6% \\ \hline 4 & 2007 & 30.9% & 25.7% \\ \hline 5 & 2008 & 12.2% & 2.8% \\ \hline 6 & 2009 & 30.4% & 11.7% \\ \hline 7 & 2010 & 27.2% & 9.5% \\ \hline 8 & 2011 & 23.3% & 5.9% \\ \hline 9 & 2012 & 52.6% & 42.1% \\ \hline 10 & 2013 & 38.3% & 42.2% \\ \hline 11 & 2014 & 30.4% & 40.4% \\ \hline 12 & 2015 & 27.4% & 13.4% \\ \hline 13 & 2016 & 4.4% & 0.2% \\ \hline 14 & 2017 & 44.2% & 25.4% \\ \hline 15 & & \\ \hline \end{tabular}