Calculate the standard deviation and return of a portfolio consisting of 60% of Security A and 40% of Security B. Assume the correlation coefficient between stock A and stock B is 0.55. Interpret the benefit of a portfolio over individual stock investment (in case of security A and B).

Year         Security A return (%)           Security B return (%)

2015                      20                                          15

2016                      22                                          12

2017                      18                                          11

2018                      15                                          10

2019                      11                                          11

( The above question contains 20 Marks. Please elaborate answer min of 600 words )