Mean, Median, Mode

The Hook

Finding the 'Average'.

What is it?

Measures that identify the central point of a dataset: Mean (Arithmetic Average), Median (Middle Value), Mode (Most Frequent).

Time Travel (History)

The concept of 'Average' was popularized by Adolphe Quetelet to define the 'Average Man' (l'homme moyen) in sociology.

Cheat Code

Mean is Mean (math work). Median is the Median Strip (middle of road). Mode is Most (popular).

Practice This Now!

The Field Guide

In Plain English: Data is messy. We need one number to represent the whole pile. Mean is the fair share. Median is the exact midpoint (good for ignoring billionaires in wealth stats). Mode is just a popularity contest.

In The Real World: Real Estate. Home prices are always listed as 'Median Price' because one mega-mansion would skew the 'Mean' way too high.

How To Do It

Mean: Add all numbers, divide by the count.
Median: Sort numbers from small to big. Pick the middle one. (If 2 in middle, average them).
Mode: Count how many times each number appears. Pick the winner.

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Booby Trap!

Thinking Mean and Median are the same. In skewed data (like income), they are very different.

Real World Challenge

"A student scores 0, 100, 100 on three quizzes. Which measure makes them look best?"

The Logic: Mean is (200/3) = 66. Median is 100 (0, 100, 100). Mode is 100. Median and Mode make them look like an A student.

Training Drills

Data Set

[2, 5, 5, 9]

Mean=5.25, Median=5, Mode=5