Delta, United, and American Airlines announced purchases of planes on July $18(7/18),$

February $12(\frac{2}{12}),$ and October $7(\frac{10}{7}),$ respectively.

Given the above information, calculate the cumulative abnormal return $($CAR$)$ for these

stocks as a group. All of the stocks have a beta of $1$ and no other announcements are

made. $($A negative answer should be indicated by a minus sign. Leave no cells blank $-$

be certain to enter $"0"$ wherever required. Do not round intermediate calculations and

round your answers to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$