Statistics for data analysts
42 levels in 7 chapters
Learn the statistics every analyst job expects: averages that lie, spread, sampling, A/B tests, correlation and honest charts, computed in pandas on real store data.
You can say which average to report, how sure a number is, whether a test result is real, and which chart answers the question, and back each claim with code. Every level is open; the path only suggests an order.
Chapter 1 · 7 levels
Describing data
- Why the average order liesNot started, difficulty 1 of 5 Next up
- Percentiles for the free-shipping thresholdNot started, difficulty 2 of 5 Next up
- One raise, two averagesNot started, quiz, difficulty 2 of 5 Next up
- How spread out are our orders?Not started, difficulty 2 of 5 Next up
- Outlier or error?Not started, quiz, difficulty 3 of 5 Next up
- Which channel's sales are steadier?Not started, difficulty 3 of 5 Next up
- Boss Boss: the order value report, done rightNot started, boss, 3 steps, difficulty 3 of 5 Next up
Chapter 2 · 6 levels
Distributions and sampling
- Order value bandsNot started, difficulty 2 of 5 Next up
- How deep do visitors browse?Not started, quiz, difficulty 2 of 5 Next up
- A sample of 200 ordersNot started, difficulty 2 of 5 Next up
- The email-only estimateNot started, quiz, difficulty 2 of 5 Next up
- Read the box plotNot started, quiz, difficulty 2 of 5 Next up
- Boss Boss: how big should the sample be?Not started, boss, 3 steps, difficulty 4 of 5 Next up
Chapter 3 · 6 levels
Comparing groups and A/B tests
- Desktop versus mobile conversionNot started, difficulty 2 of 5 Next up
- How sure is the mobile rate?Not started, difficulty 3 of 5 Next up
- What p = 0.03 actually saysNot started, quiz, difficulty 3 of 5 Next up
- Test the test with an A/A splitNot started, difficulty 4 of 5 Next up
- The test that won by peekingNot started, quiz, difficulty 3 of 5 Next up
- Boss Boss: plan the banner testNot started, boss, 3 steps, difficulty 4 of 5 Next up
Chapter 4 · 6 levels
Correlation and regression
- Do pricier products sell less?Not started, difficulty 2 of 5 Next up
- Does marketing spend drive revenue?Not started, quiz, difficulty 2 of 5 Next up
- Fit a line to spend and revenueNot started, difficulty 3 of 5 Next up
- Can the line forecast a bigger budget?Not started, quiz, difficulty 3 of 5 Next up
- Which product numbers move together?Not started, difficulty 3 of 5 Next up
- Boss Boss: the channel that looks worseNot started, boss, 3 steps, difficulty 4 of 5 Next up
Chapter 5 · 7 levels
Choosing and reading charts
- Which chart answers the question?Not started, quiz, difficulty 1 of 5 Next up
- The bar that looks four times tallerNot started, difficulty 2 of 5 Next up
- Six lines or six small chartsNot started, quiz, difficulty 2 of 5 Next up
- Smooth the daily revenue chartNot started, difficulty 3 of 5 Next up
- Parts of a whole, without the pieNot started, quiz, difficulty 2 of 5 Next up
- Design the CEO dashboardNot started, quiz, difficulty 3 of 5 Next up
- Review the momentum chartNot started, quiz, difficulty 3 of 5 Next up
Chapter 6 · 6 levels
Boss: the promo test write-up
- Check the split before the resultNot started, difficulty 2 of 5 Next up
- Conversion per arm and the liftNot started, difficulty 2 of 5 Next up
- Is the lift real?Not started, difficulty 3 of 5 Next up
- The tablet resultNot started, quiz, difficulty 3 of 5 Next up
- Write the conclusionNot started, quiz, difficulty 3 of 5 Next up
- Boss Boss: write up the spring testNot started, boss, 4 steps, difficulty 4 of 5 Next up
Chapter 7 · 4 levels
Loans, savings and what-if
- What will the racking loan cost each month?Not started, difficulty 2 of 5 Next up
- Save for it, or borrow and repay?Not started, difficulty 3 of 5 Next up
- The payment that came out twelve times too bigNot started, quiz, difficulty 2 of 5 Next up
- Boss Boss: what can we afford?Not started, boss, 3 steps, difficulty 4 of 5 Next up
Megan Collins · Head of Sales
"The board deck says our average order is about $540, and the new campaign is built around 'customers who spend $540'. That number feels high to me. What does a typical order actually look like?"
Light the next lantern