Could you please help explain and answer the following question? Thank you.

Two independent methods of forecasting based on judgment and experience have been prepared each month for the past 10 months. The forecasts and actual sales are as follows: Month 1 2 3 4 5 6 7 8 9 10 Sales 771 790 794 776 772 770 761 774 792 794 Forecast 1 775 790 795 779 772 773 759 774 791 797 Forecast 2 776 792 796 780 771 774 756 774 792 794 a. Compute a tracking signal for the 10th month for each forecast using the cumulative error for months 1 to 10. Use action limits of + 4. Is there bias present? (Do not round your intermediate calculations. Round your answers to 2 decimal places. Negative amounts should be indicated by a minus sign.) Tracking Signal Bias Forecast Method 1 Method 2 b. Compute 2s control limits for each forecast. (Do not round your intermediate calculations. Round your answers to 2 decimal places.) Control Limits Forecast Method 1 Method 2