Module 2: Sampling & Uncertainty

Big Idea

Sampling creates randomness in estimates. Sampling is why statistics exists: estimates vary because data is finite.

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Core Concept

A sample mean is not a fixed truth. It is one draw from a distribution of possible sample means.

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Visual Intuition

When we repeat sampling, the mean changes each time.

(Insert plot here)

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Interactive Simulation ⭐

Try it yourself:

👉 CLT Demo

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Quick Practice

1. What happens to the spread of sample means as n increases?
2. Does the population distribution change?
3. Why does the histogram become more normal?

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Key Takeaways

• Sampling creates uncertainty
  
• Larger samples reduce variance
  
• CLT explains why averages stabilize