Question

Tolong bantu dengan caranya no 19-20.

Answer 1

Nomer 19
Diketahui data:

(x₁ + x₂ + x₃ + x₄ + ... + x₁₀)/10 = x₀

10x₀ = x₁ + x₂ + x₃ + ... + x₁₀

Karena datanya dirubah, maka

(x₁/2 + 2) + (x₂/2 + 4) + (x₃/2 + 6) + ... + (x₁₀/2 + 20)
= (1/2)(x₁ + x₂ + x₃ + ... + x₁₀) + (2 + 4 + 6 + ... + 20)
= (1/2)(10x₁₀) + (10/2)(2 + 20)
= 5x₀ + 110

Sehingga rata-rata ubahan,

Rata-rata = (5x₀ + 110)/10
                = (1/2)x₀ + 11

Jawab : C


Nomer 20
Karena banayk siswa = 30 orang, maka

1 + 1 + a + 9 + b + 6 + 2 = 30
⇒ 19 + a + b = 30
⇒ a + b = 30 - 19
⇒ a + b = 11

Jawab ; B


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