Variable and Mathematical Expectation
Between Sylvestre-François Lacroix in 1816 and Louis Bachelier in 1914, the concepts random variable and mean of a random variable were invented. Some authors contend that Simeon-Denis Poisson invented the concepts random variable and expected value. Simeon-Denis Poisson, a French mathematician known for his work on probability theory. Poisson’s research was mainly on Probability. In 1838, Poisson published his ideas on probability theory, which also included what is now known as Poisson distribution. He published between 300 and 400 mathematical works including applications to electricity and magnetism, and astronomy.