📚 Year 9 Edexcel Statistics: Quick Vocabulary Terminology Guide | Year 9 Edexcel 统计：词汇术语速记指南
Building a strong foundation in Statistics begins with mastering the essential vocabulary. This guide covers the key terms you will meet in Year 9 Edexcel Statistics, presented in a simple, bilingual format to help you learn and remember them faster. Each English definition is immediately followed by its Chinese equivalent, and examples are provided throughout to make the concepts stick.
打好统计基础要从熟记核心词汇开始。本指南涵盖了 Year 9 Edexcel 统计课程中你会遇到的关键术语，采用简洁的双语对照形式，帮助你更快地学习并牢记。每个英文定义后立即给出对应的中文解释，并贯穿实例，让概念更牢固。
1. Core Concepts of Data | 数据的核心概念
Population refers to the entire set of individuals or items that you want to study. For example, if you are investigating the heights of all Year 9 students in your school, that group is your population.
Population（总体） 指的是你想要研究的全体个体或项目的集合。例如，如果你在调查全校 Year 9 学生的身高，那么这个群体就是你的总体。
A sample is a smaller group selected from the population. It is used to draw conclusions about the population without having to collect data from every individual.
Sample（样本） 是从总体中选出的一个较小的组。我们通过样本来推断总体的特征，而不必从每一个个体那里收集数据。
A variable is any characteristic that can take different values from one member of the population to another. Height, test score, and favourite colour are all variables.
Variable（变量） 是总体中不同成员可能取不同值的任何一种特征。身高、考试分数和最喜欢的颜色都是变量。
2. Data Types: Qualitative and Quantitative | 数据类型：定性数据与定量数据
Qualitative data (also called categorical data) describes qualities or categories that cannot be measured with numbers. Examples include hair colour, type of pet, or favourite subject.
Qualitative data（定性数据）（也称分类数据）描述的是无法用数字测量的性质或类别。例如，发色、宠物种类或最喜欢的科目。
Quantitative data consists of numerical values that can be measured or counted. Test marks, temperatures, and shoe sizes are quantitative.
Quantitative data（定量数据） 由可以测量或计数的数值组成。考试分数、温度和鞋码就属于定量数据。
Quantitative data can be further divided into discrete and continuous. Discrete data can only take specific, separate values—often whole numbers (e.g., number of siblings). Continuous data can take any value within a range and is usually the result of measuring (e.g., height of a plant).
定量数据可进一步分为离散数据（discrete）和连续数据（continuous）。离散数据只能取特定的、分开的值，通常是整数（例如兄弟姐妹的数量）。连续数据可以在一个范围内取任意值，通常是测量的结果（例如植物的高度）。
3. Collecting Data: Primary and Secondary | 数据的收集：一手数据与二手数据
Primary data is information that you collect yourself, first-hand, for a specific purpose. Carrying out a questionnaire or conducting an experiment are ways to gather primary data.
Primary data（一手数据） 是你自己为特定目的直接收集的信息。进行问卷调查或开展实验都是收集一手数据的方式。
Secondary data is information that was collected by someone else for a different reason. Examples include data from textbooks, government reports, or the internet.
Secondary data（二手数据） 是其他人为了其他原因已经收集好的信息。例如，教科书、政府报告或互联网上的数据。
A census collects data from every member of the population. It gives very accurate results but can be time-consuming and expensive. A survey usually collects information from a sample and is quicker.
Census（普查） 向总体中的每一个成员都收集数据。它给出非常准确的结果，但可能耗时且昂贵。Survey（调查） 通常仅从样本中收集信息，速度更快。
4. Organising Data: Frequency and Tables | 数据的整理：频数与表格
Frequency is the number of times a particular value or category occurs in a data set. Recording frequencies in a frequency table helps you see patterns quickly.
Frequency（频数） 是数据集中某个特定值或类别出现的次数。将频数记录在频数表（frequency table）中有助于你快速看清分布规律。
A tally is a quick way of counting frequencies. Each observation is marked with a stroke, and every fifth stroke crosses the previous four to make groups of five easy to count.
Tally（划记） 是快速计算频数的方法。每观测到一个数据就画一道记号，第五笔将前四笔记号划掉，形成一组五个，方便清点。
When data is grouped, we use class intervals. For instance, instead of listing individual heights, we might group them as 150 ≤ h < 160. The modal class is the interval with the highest frequency.
当数据分组时，我们使用组距（class interval）。例如，我们不逐个列出身高，而是将其分组为 150 ≤ h < 160。众数组（modal class） 就是频数最高的那个组距。
5. Visual Representations: Charts and Graphs | 数据可视化：图表
A bar chart represents qualitative or discrete data using rectangular bars of equal width. The height of each bar corresponds to its frequency. Bars are separated by gaps to show that the categories are distinct.
Bar chart（条形图） 用等宽的长方形条柱表示定性或离散数据。每个条柱的高度对应其频数。条柱之间留有空隙，表示各类别是不同的。
A pie chart shows data as sectors of a circle, where each sector angle is proportional to the frequency. They are useful for showing proportions of a whole.
Pie chart（饼图） 将数据表示为圆的扇形，每个扇形的角度与频数成比例。在展示部分占整体的比例时非常有用。
A histogram looks like a bar chart but is used for continuous data or grouped discrete data. There are no gaps between the bars, and often the area of each bar represents frequency, especially when class widths differ.
Histogram（直方图） 看起来像条形图，但用于连续数据或分组的离散数据。条柱之间没有空隙，且通常每个条柱的面积表示频数，尤其当组距宽度不同时。
A line graph plots points connected by straight lines, commonly used to show trends over time.
Line graph（折线图） 将数据点用直线连接起来，常用于展示随时间变化的趋势。
6. Averages: Mean, Median, Mode | 平均数：均值、中位数、众数
The mean is the sum of all data values divided by the number of values. It is also called the arithmetic average. For grouped data, we estimate the mean using midpoints of intervals.
Mean（均值） 是所有数据值之和除以数据的个数。它也称为算术平均数。对于分组数据，我们使用组中值来估算均值。
The median is the middle value when the data is arranged in order. If there is an even number of values, the median is the mean of the two middle values. The median is less affected by extreme values (outliers) than the mean.
Median（中位数） 是数据按顺序排列后位于中间的值。如果有偶数个数据，中位数就是中间两个值的均值。与均值相比，中位数受极端值（异常值）的影响较小。
The mode is the value that occurs most often. A set may have one mode, more than one mode (bimodal or multimodal), or no mode at all. For grouped data, we look for the modal class.
Mode（众数） 是出现次数最多的值。一个数据集可能有一个众数、多个众数（双众数或多众数）或根本没有众数。对于分组数据，我们寻找众数组。
7. Measures of Spread: Range and Quartiles | 离散程度的度量：极差与四分位数
The range is the difference between the largest and smallest values. It is the simplest measure of spread, but it can be heavily influenced by outliers.
Range（极差） 是最大值与最小值之差。它是最简单的离散程度度量，但会受到异常值的严重影响。
Quartiles divide an ordered data set into four equal parts. The lower quartile (Q₁) is the median of the lower half of the data; the upper quartile (Q₃) is the median of the upper half. The second quartile (Q₂) is the median.
Quartiles（四分位数） 将有序数据集分成四个相等的部分。下四分位数 (Q₁) 是数据下半部分的中位数；上四分位数 (Q₃) 是数据上半部分的中位数。第二四分位数 (Q₂) 就是中位数。
The interquartile range (IQR) is the difference between the upper and lower quartiles: IQR = Q₃ − Q₁. It measures the spread of the middle 50% of the data and is not affected by outliers.
Interquartile range（四分位距，IQR） 是上四分位数与下四分位数之差：IQR = Q₃ − Q₁。它测量中间 50% 数据的离散程度，不受异常值影响。
8. Box Plots: The Five-Number Summary | 箱线图：五数概括
A box plot (or box-and-whisker plot) visually shows the five-number summary: minimum, lower quartile (Q₁), median (Q₂), upper quartile (Q₃), and maximum. The box represents the IQR, and the ‘whiskers’ extend to the minimum and maximum values that are not outliers.
Box plot（箱线图）（也称箱须图）直观地展示五数概括：最小值、下四分位数 (Q₁)、中位数 (Q₂)、上四分位数 (Q₃) 和最大值。箱子代表四分位距，“须”延伸至非异常值的最小值和最大值。
Box plots are excellent for comparing the spread and central tendency of two or more data sets side by side. Outliers are often plotted as individual points beyond the whiskers.
箱线图非常适合并排比较两个或多个数据集的离散程度和集中趋势。异常值通常被绘制为须线以外的独立点。
To draw a box plot, you first need to find the five-number summary from an ordered list or a cumulative frequency diagram.
绘制箱线图，你首先需要从有序列表或累积频数图中找出五数概括。
9. Scatter Graphs and Correlation | 散点图与相关性
A scatter graph (scatter plot) displays pairs of quantitative data to see if there is a relationship between them. Each point represents one pair of values (x, y).
Scatter graph（散点图） 显示成对的定量数据，以观察它们之间是否存在关系。每个点代表一对值 (x, y)。
Correlation describes the direction and strength of the relationship between two variables. If y tends to increase as x increases, the correlation is positive. If y tends to decrease as x increases, it is negative. If no pattern is visible, there is no correlation.
Correlation（相关性） 描述两个变量之间关系的方向和强度。如果 y 随 x 增加而增加，相关性为正（positive）。如果 y 随 x 增加而减少，则为负（negative）。如果没有明显的规律，就是不相关（no correlation）。
A line of best fit is a straight line drawn on a scatter graph that best represents the trend. It should have roughly equal numbers of points on either side. This line can be used to make predictions, but extrapolation (predicting beyond the data range) can be unreliable.
Line of best fit（最佳拟合线） 是在散点图上绘制的一条最能代表趋势的直线。线两侧的点数应大致相等。这条线可用于预测，但外推（预测数据范围以外的点）可能不可靠。
10. Basic Probability Terms | 基础概率术语
An experiment in probability is a repeatable process that gives rise to outcomes. Tossing a coin or rolling a die are experiments.
概率中的实验（experiment） 是一种可重复的过程，会产生不同的结果。抛硬币或掷骰子都是实验。
An outcome is a possible result of an experiment. For a die, the outcomes are 1, 2, 3, 4, 5, and 6.
Outcome（结果） 是实验的一个可能结果。对于骰子，结果就是 1,2,3,4,5,6。
An event is a set of one or more outcomes. ‘Rolling an even number’ is an event that includes the outcomes 2, 4, and 6.
Event（事件） 是由一个或多个结果组成的集合。“掷出偶数”是一个事件，包括结果 2、4 和 6。
The probability of an event can be written as a fraction, decimal, or percentage, and always lies between 0 (impossible) and 1 (certain). When all outcomes are equally likely, P(event) = number of favourable outcomes / total number of outcomes.
事件的概率（probability） 可写成分数、小数或百分数，且总是在 0（不可能）和 1（必然）之间。当所有结果等可能时，P(事件) = 有利结果的数量 / 所有可能结果的总数。
Relative frequency is an estimate of probability based on the results of an experiment or survey: relative frequency = frequency of the event / total number of trials. As the number of trials increases, relative frequency tends to get closer to the theoretical probability.
Relative frequency（相对频数） 是基于实验或调查结果对概率的估计：相对频数 = 事件的频数 / 试验总次数。随着试验次数的增加，相对频数会趋近于理论概率。
Published by TutorHao | Statistics Revision Series | aleveler.com
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