Week 9 · Readings & resources

Week 9 — Readings & Resources

Introduction to Statistics Free sample edition

Your primary reading is Chapter 9 (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 10 items (4 readings and 6 videos). Allow 69–82 minutes for everything. Each group points back to the matching chapter section and class-session segment, 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 (17–21 min total)

① What does a bell promise? The normal model and the 68–95–99.7 rule

Chapter 9, Section “The empirical rule: read 68, 95, and 99.7 off the bell” · Session 1, Segment 1, “The normal model and the empirical rule” · Remember: a normal model is a bell set by its mean and standard deviation, and you always state it as an assumption.

The Normal Distribution: Crash Course Statistics #19 — CrashCourse — a lively tour of why the bell shows up so often and where it does not, with everyday examples. Stop here before sampling distributions; next week takes that up. (video, 11 min) (captions: creator)
The Normal Distribution and the 68-95-99.7 Rule (5.2) — Simple Learning Pro — a calm, step-by-step look at the rule, with a worked example that marks one, two, and three standard deviations on a number line. (video, 9 min) (captions: automatic)
Normal Distribution — Math is Fun — the gentlest page on this list; read the opening bell-curve examples and the Standard Deviations part for the 68, 95, and 99.7 percent pattern; the packaging example near the end is optional. (reading, 8–12 min)
Probability Distributions — Seeing Theory — a free interactive page; in the continuous part, pick the normal and drag its mean and standard deviation to watch one move the bell and the other widen it. (reading, 6–10 min)

② From a value to a share, and back

Chapter 9, Section “Forward calculations: from a value to a proportion” · Session 1, Segment 2, “Forward and inverse normal calculations” · Remember: the table gives the area to the left of z; for an inverse question, find z first and then turn it back into the variable's units.

Finding Areas Using the Standard Normal Table (for tables that give the area to left of z) — jbstatistics — careful table reading for areas below, above, and between two values, the same table this course uses. This builds on Week 8's work with z-scores as relative standing. (video, 6 min) (captions: automatic)
Finding Percentiles Using the Standard Normal Table (for tables that give the area to left of z) — jbstatistics — the table read backward: start from an area, find z, then turn z into a value. (video, 8 min) (captions: automatic)
Bell Shaped Curve: Normal Distribution In Statistics — Simply Psychology — read the part on converting raw scores to z-scores for a second explanation of standardizing: every normal model turns into the standard normal distribution, with mean 0 and standard deviation 1, and the sign of z tells you which side of the mean a value sits on. Use it while completing the Week-9 module overview. (reading, 3–5 min)
How to Use Excel's Normal Distribution Function =NORM.DIST and =NORM.INV — Learn Something — the spreadsheet route for both directions; the same two functions work in Google Sheets. (video, 6 min) (captions: automatic)

③ Should you trust the bell? Checking a normal model

Chapter 9, Section “Checking the model: decide whether a normal model is reasonable” · Session 2, Segment 3, “Checking whether a normal model is reasonable” · Remember: points near a straight line suggest a normal model is reasonable, and a steady bend suggests skew.

Quantile-Quantile Plots (QQ plots), Clearly Explained!!! — StatQuest with Josh Starmer — a short, picture-first explanation of how a quantile plot lines data up against a normal model, which is the idea behind the normal probability plot. (video, 7 min) (captions: automatic)

Optional one-stop reference (free online reference)

1.3.3.21. Normal Probability Plot — NIST/SEMATECH e-Handbook of Statistical Methods — a free government reference; read the purpose and the interpretation paragraphs on straight lines and departures from them, and skip the software notes. (reading, 5–8 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