tolong bantu kak..yg no 3

[tex]mean = \frac{x1f1 + ...xnfn}{n} \\ mean = \frac{4 (6) + 5(3) + 6(9) + 7(8) + 8(7) + 9(5) + 10(2)}{6 + 3 + 9 + 8 + 7 + 5 + 2} \\ mean = \frac{24 + 15 + 54 + 56 + 56 + 45 + 20}{40} \\ mean = \frac{270}{40} \\ mean = 6.75[/tex]
Jawaban : b. 6,75

Maaf Kalau Salah