The following table reports the percentage of stocks in a portfolio for nine quarters from 2007 to 2009:
|
Quarter
1st-2007
|
Stock %
29.8
|
|
2nd-2007
|
31.0
|
|
3rd-2007
|
29.9
|
|
4th-2007
|
30.1
|
|
1st-2008
|
32.2
|
|
2nd-2008
|
31.5
|
|
3rd-2008
|
32.0
|
|
4th-2008
|
31.9
|
|
1st-2009
|
30.0
|
a. Construct a time series plot. What type of pattern exists in the data?
b. Use exponential smoothing to forecast this time series. Using Excel Solver or LINGO find the value of athat minimizes the sum of squared error.
c. What is the forecast of the percentage of stocks in a typical portfolio for the second quarter of 2009?