Lessons
1Descriptive statisticsSummarise a column honestly with centre, spread and shape - mean vs median, IQR, standard deviation and percentiles.7 min
2Probability & distributionsProbability rules, random variables, and the normal, binomial and Poisson distributions you will actually meet in business data.7 min
3Sampling & the central limit theorem in practiceWhy random samples work, how sampling bias creeps in, and a simulation that makes the CLT concrete.7 min
4Confidence intervals that decision-makers understandBuild and interpret confidence intervals for means and proportions with scipy, statsmodels and the bootstrap.6 min
5Hypothesis testingSet up H0 and H1, run t-tests with scipy, read p-values correctly and report an effect size next to them.7 min
6A/B testing for business, with a Bayesian viewPlan sample sizes, run a conversion A/B test, avoid peeking, and read results the Bayesian way.8 min
7Chi-square & ANOVA testsTest relationships between categories with chi-square and compare several group means with one-way ANOVA.7 min
8Correlation, causation & regression basicsMeasure relationships with Pearson and Spearman, fit a simple regression, and avoid mistaking correlation for cause.7 min