tolong bantu jawab yaa pake cara jgan ngasal makasii

Xgab= (f1.x1)+(f2.x2)/f1+f2
Xgab=(21 x 62)+(28 x 69)/21+28
Xgab= 1,302+1,932/49
Xgab= 3,234/49
maka nilai rata-rata jika kelas A dan B digabung = 66

rata" gab=n1.x1+n2.x2/n1+n2
rata" gab= 21.62+28.69/21+28
rata" gab=1302+1932/49
rata" gab=3234/49=66
jadi rata" gabungannya adlh 66