Use the data in ATTEND for this exercise.In the model of Example $6\mathrm{.}3,$ argue that$()$

Astndfnl$/$priGPA$$$,+2$priGPA $+$ B$.$atndrte.

Use equation $(6\mathrm{.}19)$ to estimate the partial effect when priGPA $=2\mathrm{.}59$ and atndrte $=82$Interpret your estimate.$($i$)$Show that the equation can be written as

stndfnl$=0,+$ B$,$atndrte $+0,$priGPA$+$ $,$ACT$+$ $($priGPA$-2\mathrm{.}59)2+$BAC$+$BpriGPA$($atndrte$-82)+$ u$,$

where $0,=8,+28,(2\mathrm{.}59)+$ B$.(82).($Note that the intercept has changed, but this is unim.portant.$)$ Use this to obtain the standard error of $0,$ from part $($i$).$Suppose that, in place of priGPA$($atndrte $-82),$ you put $($priGPA$-2\mathrm{.}59)($atndrte $-82).($iii$)$Now how do you interpret the coeffcients on atndrte and priGPA?