Jawabanmu

2014-04-30T19:49:30+07:00
83=(85+76+80+92+x)/5
415=33+x
x=82 
taraaa :D 
1 5 1
2014-04-30T19:54:14+07:00
 85, 76, 80, 92 ratarata = 83,25
5x83= 415
4x83,25= 333

selisih 415-333 = 82