设总体X~N(μ,σ²),其中μ未知,
为来自该总体的样本,在μ的无偏估计
Passage One
Kids often ask Scout Bassett, of Palm Desert, California, if she wishes she had two normal legs. Bassett, 18, answers, “No. I have never known anything different, and it would seem weird to me. Besides, if it weren’t for the missing le