Standard & Poor's 500 Composite Stock Index (S&P 500) is a stock market index. Like the Dow

Question:

Standard & Poor's 500 Composite Stock Index (S&P 500) is a stock market index. Like the Dow Jones Industrial Average, it is an indicator of stock market activity. The data in the table are end-of-quarter values of the S&P 500 for the years 2008-2015.
a. Calculate and plot the exponentially smoothed series for the quarterly S&P 500 using a smoothing constant of w = .3.
b. Repeat part a but use w = .7.
c. Which exponentially smoothed series do you prefer for describing trends in the series? Explain.