A.0,56 B.0,48 C.0,46 D.0,36 Pake cara

rata-rata hulu :
(2.9 + 2.2 + 5 + 4.7 + 5.1) / 5 = 19.9 / 5 = 3.98

rata-rata hilir :
(1.8 + 4.7 + 6.8 + 1.8 + 7.2) / 5 = 22.3 / 5 = 4.46

Selisih = 4.46 - 3.98 = 0.48