Tolong ya kak pakai cara ngrjainny......Makasih sblmny

rata - rata = (60x2) + (70x3) + (80x3) + (90x1) + (100x1)
                = 120 + 210 + 240 + 90 + 100
                = 760 : (2+3+3+1+1)
                = 760 : 10
                = 76