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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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70 min total

12 Lessons

0 Completed

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.

5 minArticle

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When Averages Lie Quiz

Test what you just read.

3 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.

11 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.

5 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.

12 minVideo

Start

Spotting the Shape

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

5 minArticle

Start

Spotting the Shape Quiz

Test what you just read.

3 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.

10 minVideo

Start

Spotting Sampling Bias

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

5 minArticle

Start

Spotting Sampling Bias Quiz

Test what you just read.