Delta, United, and American Airlines announced purchases of planes on July $18(7/18),$ February $12(2/12),$ and October $7(10/7),$ respectively.

$\backslash$table$[[$Delta$,$United,American$],[,$Market,Company,,Market,Company,,Market,Company$],[$Date$,$Return,Return,Date,Return,Return,Date,Return,Return$],[7/12,-\mathrm{.}33,-\mathrm{.}45,\frac{2}{8},-\mathrm{.}82,-1\mathrm{.}04,10/1,\mathrm{.}53,\mathrm{.}28],[\frac{7}{13},\mathrm{.}00,\mathrm{.}23,\frac{2}{9},-\mathrm{.}92,-1\mathrm{.}04,\frac{10}{2},\mathrm{.}43,\mathrm{.}65],[7/16,\mathrm{.}52,\mathrm{.}76,\frac{2}{10},\mathrm{.}43,\mathrm{.}19,\frac{10}{3},1\mathrm{.}13,1\mathrm{.}13],[7/17,-\mathrm{.}52,-\mathrm{.}28,2/11,\mathrm{.}63,1\mathrm{.}43,\frac{10}{6},\mathrm{.}13,-\mathrm{.}91],[7/18,-2\mathrm{.}12,1\mathrm{.}24,\frac{2}{12},-\mathrm{.}33,-\mathrm{.}08,\frac{10}{7},-2\mathrm{.}23,-\mathrm{.}29],[7/19,-\mathrm{.}87,-\mathrm{.}63,\frac{2}{15},1\mathrm{.}13,1\mathrm{.}56,\frac{10}{8},\mathrm{.}53,\mathrm{.}53],[\frac{7}{20},-\mathrm{.}92,-1\mathrm{.}06,\frac{2}{16},\mathrm{.}53,\mathrm{.}53,\frac{10}{9},-\mathrm{.}33,-\mathrm{.}19],[\frac{7}{23},\mathrm{.}73,\mathrm{.}48,\frac{2}{17},-\mathrm{.}33,-\mathrm{.}19,\frac{10}{10},\mathrm{.}33,-\mathrm{.}09],[\frac{7}{24},\mathrm{.}23,\mathrm{.}10,\frac{2}{18},\mathrm{.}33,\mathrm{.}18,\frac{10}{13},\mathrm{.}00,-\mathrm{.}13]]$

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$.,32\mathrm{.}16.)$

$\backslash$table$[[\backslash$table$[[$Days from$],[$announcement$]],$Abnormal returns $(R_i-R_M),\backslash$table$[[$Average abnormal$],[$return$]],\backslash$table$[[$Cumulative$],[$abnormal return$]]],[$Delta$,$United,American,Sum$],[-4],[-3],[-2],[-1],[0],[1],[2],[3,,,,,,],[4,,,,,,]]$