Question 3 (15pt): The last five years of return for stock are:

Year

2015

2016

2017

2018

2019

Return relatively

-20%

10%

50%

30%

25%

1.What is the average return of stock in two methods (Arithmetic mean return and geometric mean return)

2.What is the variance, standard deviation of stock return

3.If we use arithmetic mean return of period 2015 - 2019 to forecast about the return of 2020. What is 95% confidence interval for 2020's return? (Using normal distribution)