Jawabanmu

2014-04-21T11:04:05+07:00
R39 = 45
n= 39

R1= x
n=1


45.39 + 1.x
----------------------- = 46
   40


40.46 = 45.39 +1x
1840 = 1755 + 1x
1840-1755= 1x
85=x

nilai Rina = 85
2014-04-21T11:09:59+07:00
Nilai 39 siswa = 39x45=1755:39=45
nilai rina = 40x46=1840 = 1755 - 1840 = 85
pembuktian = (39x45+85)/40=(1755+85)/40=1840/40=46
 tolong dibuat terimakasih ya!!