Week 8 — Readings & Resources
Your primary reading is Chapter 8 (in this module). Everything below is the optional, go-deeper layer — pick what helps, skip the rest.
How to use this page
This page has 11 items (5 readings and 6 videos). Allow 74–91 minutes for everything. The first two groups go deeper on this week's new idea, the z-score, and the last two help you review for the midterm, so use the full menu when you want more practice, or take the quick path below.
Every video here has captions: turn them on with the CC button in the player. The chapter covers the same ideas in text.
Pick-one quick path (19–23 min total)
- Z-Scores and Percentiles: Crash Course Statistics #18 — CrashCourse
- Normal Distribution — Math is Fun
① How far from typical? Measuring relative standing
Chapter 8, Section “Measure relative standing with a z-score” · Session 2, Segment 4, “Relative standing with z-scores” · Remember: subtract the mean, then divide by the standard deviation, and say the result in standard deviations.
- Z-Scores and Percentiles: Crash Course Statistics #18 — CrashCourse — a lively tour of why we standardize, built around comparing scores on two different tests. Watch the z-score part closely; the percentile part leans on the normal curve, which comes next week. (video, 11 min) (captions: creator)
- How to Calculate z-Scores and Why — Wrath of Math — a short, calm walk-through of the two steps, subtract the mean and divide by the standard deviation, with a reminder of what the sign tells you. (video, 6 min) (captions: automatic)
- Normal Distribution — Math is Fun — read the Standard Scores and Why Standardize parts for a friendly height example of a z-score. Stop here before the In More Detail part and its table; next week takes up the normal model and its areas. (reading, 8–12 min)
- Standarding - Z Scores in Excel — 5E Analytics — shows the spreadsheet route, including the STANDARDIZE function, so you can check a z-score you worked by hand. (video, 4 min) (captions: automatic)
② Same value, different story: comparing across groups
Chapter 8, Section “Compare across groups: same value, different story” · Session 2, Segment 5, “Same value, different group” · Remember: a z-score has no units, so it can compare positions in groups with different centers and spreads.
- Standardizing Values by Finding Z Scores — Nicole Hamilton — a brief example that uses z-scores to compare two values measured on different scales, the same move as comparing a 4,000 g Adelie with a 4,000 g Gentoo. (video, 4 min) (captions: automatic)
- Z-Score: Definition, Formula, Calculation & Interpretation — Simply Psychology — read from the top through the Interpretation part: why a z-score lets you compare values measured on different scales, the formula with its population and sample forms, and what the sign and size of the score tell you. Then try the practice problems. Use it while completing the Week-8 module overview. (reading, 5–8 min)
③ Where did the numbers come from, and do they move together?
Chapter 8, Section “Where did the numbers come from? Check the source first” · Session 1, Segment 1, “Where the numbers came from” · Remember: ask who was measured and how before you trust a number, and treat a pattern in an observational study as association, not cause.
- Census and sample — Australian Bureau of Statistics — a clear government explainer on studying a whole population or a sample, and on random versus non-random ways of choosing who gets measured. (reading, 6–10 min)
- Correlation Doesn't Equal Causation: Crash Course Statistics #8 — CrashCourse — a review of reading a correlation and of the lurking variables that can sit behind one. (video, 12 min) (captions: creator)
④ How likely is it, and what should you expect?
Chapter 8, Section “How likely is it, and what should you expect? Use the chance rules” · Session 1, Segment 3, “Chance and expectation” · Remember: divide a conditional probability by the group you were given, and read an expected value as a long-run average.
- Expected Value and Variance of Discrete Random Variables — jbstatistics — a careful, notation-exact review of how an expected value and a standard deviation come out of a probability table. (video, 8 min) (captions: automatic)
- Basic Probability — Seeing Theory — an interactive page; this time work through the Expectation and Variance parts, where you can watch a running average settle. This builds on Week 6's work with random variables and their long-run averages. (reading, 6–10 min)
Optional one-stop reference (free online reference)
- Measures of Scale — NIST/SEMATECH e-Handbook of Statistical Methods — the standard reference for the variance and the standard deviation, the spread a z-score divides by; read those two definitions and skip the more advanced measures further down. (reading, 4–6 min)
Heads-up (links rot): these point to outside sites that occasionally move or rename pages. If a link ever fails, tell your instructor and use the reference above in the meantime.
Provenance: Built with The Course Maker · samples.thecoursemaker.com