The average of six numbers is 35. If each of the first three numbers increased by 4 and each of the remaining three is decreased by 8, then what is the new average?
The average of six numbers is 35. If each of the first three numbers increased by 4 and each of the remaining three is decreased by 8, then what is the new average?
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Let the six numbers be \(a_1, a_2, a_3, a_4, a_5, a_6\).
Given that the average of the six numbers is 35, we have:
\[
\frac{a_1 + a_2 + a_3 + a_4 + a_5 + a_6}{6} = 35
\]
Multiplying both sides by 6 gives:
\[
a_1 + a_2 + a_3 + a_4 + a_5 + a_6 = 6 \times 35 = 210
\]
After the operations, the new sum of the numbers will be:
\[
(a_1 + 4) + (a_2 + 4) + (a_3 + 4) + (a_4 – 8) + (a_5 – 8) + (a_6 – 8)
\]
\[
= (a_1 + a_2 + a_3) + 3 \times 4 + (a_4 + a_5 + a_6) – 3 \times 8
\]
\[
= (a_1 + a_2 + a_3) + 12 + (a_4 + a_5 + a_6) – 24
\]
\[
= (a_1 + a_2 + a_3 + a_4 + a_5 + a_6) + 12 – 24
\]
\[
= 210 – 12
\]
\[
= 198
\]
Therefore, the new average is:
\[
\frac{198}{6} = 33
\]
So, the new average is 33.