Problem 3-7 (Algo) Freight car loadings over an 18-week period at a busy port are as follows: Week 1 2 3 4 Number 360 375 390 375 390 400 Week 7 8 9 10 Number 430 450 470 455 475 495 Week 13 14 15 16 Number 505 515 545 560 575 590 5 6 11 12 17 18 Click here for the Excel Data File a. Determine a linear trend line for expected freight car loadings. (Round your intermediate calculations and final answers to 2 decimal places.) Y + 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 940 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 940 loadings in Week