John Graunt: The First Data Detective

John Graunt was a businessman who lived in London about 400 years ago. He was born in 1620 and died in 1674. At that time, people in London wrote down when someone died every week. These papers were called Bills of Mortality.

Graunt looked at these death records very carefully. He wanted to find patterns. He used simple math to study the numbers. He found that about the same number of people died each year, even when the exact numbers changed from week to week.

In 1662, Graunt wrote a book about his findings. This book was very important because no one had studied death numbers like this before. His work helped start the science of statistics. Other smart people noticed his work, and he became a member of the Royal Society.

Graunt was not a university student. He learned everything by himself while working in business. His ideas helped people understand how cities work and how diseases spread. Today, we still use similar methods to study population and health.