Plis jawab pake cara

70 x 1 = 70
75 x 3 = 225
80 x 7 = 560
85 x 6 = 510
90 x 4 = 360
95 x 2 = 190
100 x 1 = 100

Fi = 1+3+7+6+4+2+1 = 26
xi = 70+225+560+510+360+190+100 = 2015
Rata² = Xi : Fi = 2015 : 26 = 77.5

rata rata nilai 77.5, jadi yang diatas 77.5 lolos.
7+6+4+2+1= 20
yang tidak lolos 6