Berapa nilai rata rata?​

Nilai rata-rata 19 siswa = 19 siswa x 76 = 1444

nilai rata-rata 18 siswa = 18 siswa x 75 = 1350

nilai Fani = 1444 – 1350 = 94

nilai Firman = 94 – 10 = 84

nilai rata-rata 20 siswa = (1444 + 84) : 20

= 76,4

maaf kalo salah