Freight car loadings over an 18-week period at a busy port are as follows: Week Number Number 310 Week 7 Number 405 Week 13 1 480 2 330 8 425 14 495 3 350 9 445 15 535 4 330 10 425 16 555 5 350 11 445 17 575 6 365 12 465 18 595 a. Determine a linear trend line for expected freight car loadings. (Round your intermediate calculations and final answers to 2 decimal places.) Y = t 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 890 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 890 loadings in Week