Respuesta :

texaschic101
(210 + 159.80 + 301.25 + x) / 4 = 638.40
(671.05 + x ) / 4 = 638.40 ...multiply both sides by 4
671.05 + x = 638.40 * 4
671.05 + x = 2553.6
x = 2553.6 - 671.05
x = 1882.55 <=== the 4th number
minarohani7
may be he is right but i am not sure