Examine the following time series:

a. Produce a scatter plot of this time series. Indicate the appropriate forecasting model for this time series.
b. Construct the equation for the forecasting model identified in part a.
c. Produce forecasts for time periods 11, 12, 13, and 14.d. Obtain the forecast bias for the forecasts produced in part c if the actual time series values are - 35, - 41, - 79, and - 100 for periods 11 through 14, respectively.