# A normal bell curve that is made with humans

A picture was found at the website of the department of statistics and actuarial science at Simon Fraser University.

Though this normal bell curve is not the work of nature, the idea is clever. A picture of a normal distribution should never go to waste. So we write about it in our introductory statistics blog (see here). Indeed, it is an excellent opportunity to discuss properties of normal distribution.

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$\copyright$ 2017 – Dan Ma

# Benford’s law in Hollywood

A movie called The Accountant is a 2016 film starring Ben Affleck and Anna Kendrick.

What is notable for us here at climbingmatheverest.com is that Chris Wolff, the protagonist played by Affleck, is a crime fighter who knows how to use a gun and a spreadsheet. Though he is an expert sniper and a martial artist, his chief weapon in fighting crime is mostly statistical in nature. One tool that stands out is the so called Benford’s law, which is a statistical law used by statisticians and forensic accountants to sniff out fraudulent numbers in financial documents. Of course this being a Hollywood movie, it cannot be just rely on numbers and statistics. There are plenty of action scenes.

Here’s an interview with a forensic accountant who vouched for the authenticity in the movie on applying the Benford’s law and other statistical investigative techniques.

According to Benford’s law, the first digits of the numbers in many natural data sets follow a certain distribution. For example, the first digits are 1 about 30% of the time. Any set of financial documents that have too few 1’s should raise a giant red flag. In the movie, Wolfe spotted the unusual frequency of the first digit 3 in a series of financial transactions. Deviations between the actual frequencies of first digits in the documents and the frequencies predicted by the Benford’s law raise suspicion. Then the investigator can dig further into the numbers to look for potential frauds.

Interested in knowing more about Benford’s law? Here’s some blog posts from several affiliated blogs.

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$\copyright$ 2017 – Dan Ma