9 Freight car loadings over an 18-week period at a busy port are as follows: Week Number 290 300 310 points 300 310 315 335 Book 375 9 415 10 405 11 445 Ask 12 485 13 490 14 495 15 515 References 16 525 17 535 18 545 Click here for the Excel Data File a. Determine a linear trend line for expected freight car loadings. Note: 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. Note: 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 870 loadings per week. Assuming the current trend continues, in which week (at the earliest) should the loading volume reach that level? Note: 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 870 loadings in Week