Freight car loadings over an 18-week period at a busy port are as follows: a. Determine a linear trend line for expected freight car loadings. (Round your intermediate calculations and final answers to 3 decimal places.) b. Use the trend equation to predict expected loadings for weeks 20 and 21 . (Round your intermediate calculations and final answers to 3 decimal places.) The forecasted demand for week 20 and 21 is and respectively. c. The manager intends to install new equipment when the volume exceeds 800 loadings per week. Assuming the current trend continues, the loading volume will reach that level in approximately how many more weeks? (Round your intermediate calculations to 3 decimal places and finat answer to the nearest whole number.) It would take approximately more weeks