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Each tree’s prediction has variance $1$ and any two trees’ predictions correlate at $0.3$ . What is the variance of the average of $100$ trees, to three decimals?

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Trees: bagging, random forests and gradient boosting

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Each tree’s prediction has variance 111 and any two trees’ predictions correlate at 0.30.30.3. What is the variance of the average of 100100100 trees, to three decimals?

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Each tree’s prediction has variance $1$ and any two trees’ predictions correlate at $0.3$ . What is the variance of the average of $100$ trees, to three decimals?