2.2: 什么是频率分布

What is a Frequency Distribution
JoVE Core
Statistics
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JoVE Core Statistics
What is a Frequency Distribution

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00:51 min
April 30, 2023

Overview

A frequency is the number of times a value of the data occurs. The sum of all the frequency values represents the total number of students included in the sample. It is commonly used to group data of quantitative types. Frequency distributions can be displayed in a table, histogram, line graph, dot plot, or pie chart, just to name a few. A histogram is a graphical representation of tabulated frequencies, shown as adjacent rectangles, erected over discrete intervals (bins), with an area equal to the frequency of the observations in the interval.

In a frequency distribution table, the data values are grouped into classes of equal widths. The class boundaries are individual values chosen to separate classes (often being the midpoints between upper and lower class limits of adjacent classes), while the smallest and largest observations in each class are called class limits. Frequency distributions can typically have between 5 and 20 classes, all with equal widths, mutually exclusive, continuous, and exhaustive.

Transcript

考虑一组 50 人参加马拉松比赛。假设马拉松的组织者想知道参与者的数量如何随年龄而变化。

为了找出答案,使用频率分布表对数据进行了汇总。它是一种统计工具,表示划分为多个类别或类的数据与每个类的值数(称为频率)。

频率表有助于了解数据集中数据的出现和分布。

例如,频率表有助于根据身高可视化学生的分布。

同样,使用频率分布表可以很容易地可视化一组患者之间的脉率变化。

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