D$.$ COST BEHAVIOUR $(6$ Marks$)$

Least$-$Squares Regression

Below is assorted information using Excel about the shipping costs for a local company using the least$-$squares regression method.

$\backslash$table$[[$B$,$D$,E,$F$,$G$,$H$,1],[2,,$Shipping,Units$],[3,,$Expense,Shipped,,,,,$],[4,$January,$2200,4,,=$ SLOPE$($C$4$:C$10,$D$4$:D$10),317\mathrm{.}85],[5,$February,$3100,7,,||=$ INTERCEPT$($C$4$:C$10,$D$4$:D$10),1010\mathrm{.}71],[6,$March,$2600,5,,=$RSQ$($C$4$:C$10,$D$4$:D$10),0\mathrm{.}962221],[7,$April,$1500,2,,,,,],[8,$May,$2200,3,,,,,],[9,$June,$3000,6,,,,,],[10,$July,$3600,8,,,,,]]$

What does the SLOPE tell you? $(1$ mark$)$

What does the INTERCEPT tell you? $(1$ mark$)$

What does the RSQ tell you? $(2$ marks$)$

Provide the regression line from the Excel information above. $(2$ marks$)$