Charles Jean Gustave Nicolas de la Vallée-Poussin was responsible for proving the prime number theorem. A prime number is a number that can be divided by only one and itself without producing a remainder, and de la Vallée-Poussin--like many others--set out to prove the relationship between prime numbers. In an article for MAA Online dated December 23, 1996, Ivars Peterson asserts: "In effect, [the prime number theorem] states that the average gap between two consecutive primes near the number x is close to the natural logarithm of x. Thus, when x is close to 100, the natural logarithm of x is approximately 4.6, which means that in this range, roughly every fifth number should be a prime." De la Vallée-Poussin was additionally known for his writings about the zeta function, Lebesgue and Stieltjes integrals, conformal representation, algebraic and trigonometric polynomial approximation, trigonometric series, analytic and quasi-analytic...