Problem 3-7 Freight car loadings over an 18-week period at a busy port are as follows: points Week Sumber Week Number WeekNumber 400 415 15 525 510 eBook 415 16 17 580 510 625 640 655 11 12 18 Print a. Determine a linear trend line for expected freight car loadings. (Round your intermediate calculations and final answers to 2 decimal places.) References b. Use the above trend equation to predict expected loadings for Weeks 20 & 21. (Round your final answers to 2 decimal places.) The forecasted demand for Week 20 is and for Week 21 is c. The manager intends to install new equipment when the volume exceeds 980 loadings per week. Assuming the current trend continues, in which week (at the earliest) should the loading volume reach that level? (Use the rounded answers, as required, from any previous part of this problem. Do not round any other intermediate calculations. Round your final answer to 2 decimal places.) It should reach 980 loadings in Week D