"The normal distribution is useful because of the central limit theorem. In its most general form, under some conditions (which include finite variance), it sta

"The normal distribution is useful because of the central limit theorem. In its most general form, under some conditions (which include finite variance), it states that averages of random variables independently drawn from independent distributions converge in distribution to the normal, that is, become normally distributed when the number of random variables is sufficiently large." https://en.m.wikipedia.org/wiki/Normal_distribution https://en.m.wikipedia.org/wiki/Normal_distribution This is why engineers get frustrated with managers that pretend to know math. Employees are not selected randomly and companies like to apply curves to even medium and small departments. A normal distribution does not apply. Keep improving.