Statistical Analysis Skill

Descriptive statistics, trend analysis, outlier detection, hypothesis testing, and guidance on when to be cautious about statistical claims.

Descriptive Statistics Methodology

Choose the right measure of center based on the data:

Situation	Use	Why
Symmetric distribution, no outliers	Mean	Most efficient estimator
Skewed distribution	Median	Robust to outliers
Categorical or ordinal data	Mode	Only option for non-numeric
Highly skewed with outliers (e.g., revenue per user)	Median + mean	Report both; the gap shows skew

Always report mean and median together for business metrics. If they diverge significantly, the data is skewed and the mean alone is misleading.