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第五章 统计数字特征 概率分布与数字特征 前面已经讲过,要全面研究或解决一个有关概率论的问题,必须知道其概率分布。但是,从三个常用分布(正态分布、二项分布、泊松分布)来看,概率分布较为繁难,不便应用。对于许多实用问题,有时只需要知道一两个简单的数字,就可以把情况基本反映出来。最常用的就是平均值,例如,计算曲线外轨超高时,并不需要知道列车速度分布,只需要知道“列车平均速度”就够了。列车平均速度,就算是一种统计数字特征。
CHAPTER FIVE STATISTICAL CHARACTERISTICS PROBABILITY DISTRIBUTION AND NUMERIC CHARACTERISTICS As mentioned earlier, to fully investigate or solve a problem related to probability theory, we must know its probability distribution. However, from the three common distributions (normal distribution, binomial distribution, Poisson distribution), the probability distribution is more complicated and inconvenient to apply. For many practical problems, sometimes only need to know one or two simple numbers, you can basically reflect the situation. The most common is the average. For example, when the outer curve of the calculation curve is very high, it does not need to know the train speed distribution, but only needs to know the average train speed. The average train speed is a statistical feature.