The computer stochastic simulation test was used to study repeat number for controlling the probability of type ii errors and establish a formula calculating sample size in the ease of known historical data 利用计算机摸拟试验，从控制犯第二类错误的概率来研究两总体均值比较试验时的重复次数问题，求得在已知历史资料情况下样本容量的计算公式。
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These including : based on the reliability checkout of experiment data , the optimum fit of probability model by finite contrast method can be used to avoid type ii error and the estimation of distribution parameter with extended bayesian method to avoid the phenomenon that the results err from matrix owing to the lack of experiment data 主要做了以下工作：在土工实验数据进行可靠性检验的前提下，用优度检验的有限比较法拟合概率模型，可以避免纳伪现象的发生：用经验bayes方法估计分布参数可以解决由于实验数据不足而可能导致的估计结果背离母体的现象。
