CSCA MathematicsChapter 4: Probability & StatisticsBeginner
Statistics: Mean, Variance & Normal Distribution
数据的数字特征与正态分布 · Node 4.2
Sample mean $\bar{x}$, sample variance $s^2$, standard deviation, and normal distribution curve symmetry ($3\sigma$ rule).
Chapter Weight: 15% of official examination
Practice This NodeCore Mathematical Axiom
Formula Proof & TrapsCSCA Exam Trap Alert
Forgetting that multiplying data by constant $a$ multiplies variance by $a^2$ (not $a$).