When and why do you use lognormal distribution or normal distribution for analyzing securities? Lognormal for stocks, normal for portfolio returns.

Discover what a log-normal distribution is, its financial applications, and how to calculate it, including using Excel for ...

In the graph below, a normal distribution is shaped like a bell, hence its nickname the bell curve, with the middle of the curve representing the mean.

The bell curve has been pushed far to the right as income concentrates in upper strata households, even as the value of middle incomes have fallen.

One of the most common assumptions in data analysis is that the numbers will follow a normal distribution – a central concept in statistics often known as the bell curve.