短語(yǔ)詞組短語(yǔ)unbiased sample mean 無(wú)偏樣本均值random unbiased sample 隨機(jī)不偏樣本;隨機(jī)無(wú)偏樣本unbiased sample design 無(wú)偏樣本設(shè)計(jì) 返回 unbiased sample