When you get--this is Rituparna, counting the leaves on a tree-- you can estimate, from a sample, the population expected values.

如果你...像数叶子的睿都巴若那一样,只有部分样本的话,你可以来估计总体均值

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You don't have to count all the leaves on the tree, you can take a sample and you count that and then you multiply.

你不必数树上所有的叶子,你可以抽样,然后计数,再相乘即可

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