STATISTICS RULE COPIED! 📊

Arithmetic Mean 📊

x̄ =
Σ x n
Concept: Sum of values divided by number of values.

Statistics Key Concepts 📊

x̄
Mean

The average. Calculated by summing all values and dividing by the count.

x̃
Median

The middle value in a sorted data set. Splits the data into two equal halves.

Mo
Mode

The value that appears most frequently in a data set. Can have more than one!

σ
Std. Deviation

Measures how spread out the numbers are from the mean value.

σ²
Variance

The average of the squared differences from the Mean.

R
Range

The difference between the highest and lowest values in a data set.

Σ
Summation

A Greek letter used to represent the sum of a sequence of numbers.

!
Outlier

A data point that differs significantly from other observations.

∩
Normal Dist.

The "Bell Curve" where most data clusters around the central peak.

Legacy of Statistics 📜

Σ

ANCIENT ERA | CENSUS

Ancient Egyptians and Romans conducted the first 'Censuses' to count people for taxes and military power. The word comes from the Latin 'Status', meaning state.

1662 AD | JOHN GRAUNT

John Graunt, the "Father of Demography," was the first to analyze birth and death records in London, predicting social trends through pure data for the first time.

1800s | THE PIONEERS

Francis Galton and Karl Pearson developed the modern math behind correlation and standard deviation, turning statistics into a rigorous scientific tool.

"Did you know? During the Crimean War, Florence Nightingale used 'Rose Diagrams' (an early form of pie charts) to prove that more soldiers died from infections than from battle wounds!"