Question

No 18 sama 19 bantu donk kak bang ! :)

Answer 1

18)
n1= 42, x1 = 6
n2 =3, x2 = 8
rata sekarang = Xg
.
xG = ( n1. x1 + n2.x2)/ (n1 +n2)
Xg= (42 x 6 + 3 x8 ) / (42+3)
xG = 276/45 == 6,13
.
19.
n1 = n, x1 = 50
n2 = 1 , x2 = 70
Xg = 51
..
Xg = n1 x1 +n2 x2 / (n1+n2)
51= n(50) +(1)(70) / (n+1)
51 (n+1) = 50 n + 70
(51-50) n = 70 - 51
n = 19
banyak siswa  n + n2 = 19 +1 = 20