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Statistics Mastery

Don't calculate. Evaluate. Master the logic of data distributions and errors.

Logical Shortcut
Statistics

Standard Deviation Logic

Spread = Gap

Standard Deviation measures how "spread out" data is from the mean. On the SAT, you never calculate it; you only compare it.

📝 Example: Comparison logic

The Golden Rule:

Wider range/frequency at edges = Higher SD.
Tight cluster near mean = Lower SD.

Instant Point
Statistics

Margin of Error

Sample Size ↑ = MoE ↓

The Margin of Error (MoE) is inversely proportional to the sample size. Ask more people, get a more precise (smaller error) result.

📝 Example: MoE Shift

Survey A: 100 people. Survey B: 1000 people. Which has the smaller margin of error?

Answer: Survey B. Increasing sample size reduces error.