We seem to be surrounded by bell curves—curves more formally known as normal distributions, or Gaussian distributions. All manner of things appear to be distributed normally: people's heights, sizes of snowflakes, errors in measurements, lifetimes of lightbulbs, IQ scores, weights of loaves of bread, and so on.

The normal distribution is a symmetrical, bell-shaped distribution in which the mean, median and mode are all equal. It is a central component of inferential statistics. The standard normal distribution is a normal distribution represented in z scores. It always has a mean of zero and a standard deviation of one.

What are some real world examples of normal distribution? A normal distribution, also called the bell curve, has many real world examples. Some examples include test scores, height, shoe size, IQ, and income.