a$.$ Determine a linear trend line for expected freight car loadings. $($Round your intermediate calculations and final answers to $2$ decimal places.$)$

hat$(Y)=,+$

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 $990$ 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