本章概览：
Guide:

• 集中量数：分布的中间位置的情况，也叫集中趋势，用来估计和预测总体的情况。
  Central tendency: The situation at the middle position of a distribution, also known as concentration trend, used to estimate and predict the overall situation.
• 差异量数：描述数据分布的变异性，是对分布的延伸和聚集状态程度的定量化描述，用来衡量估计和预测的误差大小。
  Variability: describes the variability of data distribution, is a quantitative description of the extension of distribution and the degree of aggregation, used to measure the size of estimation and prediction errors.

学习要点：
Points：

1. 学会计算均值，中数和众数；
   Learn to calculate mean, median, and mode;
2. 对于给定的分数分布，确定如何选用适宜的集中量数；
   Learn how to choose the appropriate central tendency for a given score distribution;
3. 学会计算标准差，四分位距和全距；
   Learn to calculate standard deviation, interquartile range, and full range;
4. 对于给定的分数分布，确定如何选用适宜的差异量数。
   Learn how to choose the appropriate variability for a given score distribution

1. 算术平均数、中数、众数 (Arithmetic mean, median, mode)
2. 分布的形状与集中量数 (The shape of distribution and central tendency)
3. 集中量数的比较 (The comparison of central tendency)

1. 全距、标准差、四分位距 (Full range, standard deviation, interquartile range)
2. 差异量数的比较 (The comparison of variability)

• 2023第三章作业 (Chapter3 homework of 2023)
• 2024第三章作业 (Chapter4 homework of 2024)