什么区别啊！这三个

同学你好，

相关概念辨析如下：

①Absolute frequency：The actual number of observations in a given interval is called the absolute frequency。即absolute frequency是一个数字，非百分比。

②Relative Frequency.：The relative frequency is the absolute frequency of each interval divided by the total number of observations。即与absolute frequency对比，relative frequency是一个百分比，所以是relative（相对）的概念。这个百分比等于absolute frequency/total observations

③Cumulative relative frequency：The cumulative relative frequency cumulates (adds up) the relative frequencies。所以cumulative relative frequency是概念②中的relative frequency的加总，所以是cumulative（累积）的概念。这个累加出来的结果也是一个百分比。

④Cumulative absolute frequency：这个概念和③类似，是绝对频率的累加的概念。但这是一个数字（非百分比）的叠加。

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Absolute frequency有时直接简写为frequency

Cumulative absolute frequency有时直接简写为Cumulative frequency

做题目时辨别概念即可