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Stats You Can Actually Use

The foundation. Mean vs median, spread, distributions, sampling intuition. Enough stats to read a chart correctly without faking it.

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66 min total

12 Lessons

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Module Content

Mean, Median & Mode - Why Averages Lie

A short primer on the three summary statistics every analyst uses daily, and why they tell different stories about the same data. FIND_VIDEO: search 'Khan Academy mean median mode' - recommended channel: Khan Academy. Aim for 10 min or under.

10 minVideo

Start

When Averages Lie

Worked example: the same dataset, three summary numbers, two completely different boardroom stories.

6 minArticle

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When Averages Lie Quiz

Test what you just read.

2 minTutorial

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Variance, Standard Deviation & Percentiles

What 'spread' means and why p50/p90/p99 are reported the way they are. FIND_VIDEO: search 'StatQuest standard deviation percentile' - recommended channel: StatQuest with Josh Starmer. Aim for 11 min or under.

6 minVideo

Start

Reading Spread Like an Analyst

Why the same metric can have wildly different spread, and why p99 is the number engineering teams actually care about.

6 minArticle

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Reading Spread Like an Analyst Quiz

Test what you just read.

3 minTutorial

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Distributions That Matter in DA Work

Normal vs log-normal vs long-tailed: how to recognize which one you're looking at, and why it changes how you summarize it. FIND_VIDEO: search 'StatQuest normal log-normal distribution' - recommended channel: StatQuest with Josh Starmer. Aim for 12 min or under.

5 minVideo

Start

Spotting the Shape

Histograms tell stories. Read four common distribution shapes correctly and pick the right summary stats for each.

6 minArticle

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Spotting the Shape Quiz

Test what you just read.

2 minTutorial

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Sampling Intuition - Why Sample Size Matters Less Than You Think

A small random sample beats a huge biased one. This video makes that case through survey design and sampling-bias methods (stratified, cluster, non-response bias) - the recap below connects it directly to the 'size matters less than design' thesis with a real historical example. FIND_VIDEO: search 'CrashCourse sampling methods bias' - recommended channel: CrashCourse. Aim for 10 min or under.

12 minVideo

Start

Spotting Sampling Bias

A 10K-user survey can be more misleading than a 100-user one. Learn why.

6 minArticle

Start

Spotting Sampling Bias Quiz

Test what you just read.