Which term refers to the probability distribution that has a bell-shaped curve?

The term that refers to the probability distribution characterized by a bell-shaped curve is the normal distribution. This distribution is symmetric and centered around its mean, with the majority of the data points clustering around the central peak. As you move away from the mean, the probabilities decrease, resulting in the recognizable bell shape. The normal distribution is fundamental in statistics due to the central limit theorem, which states that, under certain conditions, the sum of a large number of random variables will tend to be normally distributed, regardless of the original distribution of the variables.

In contrast, the log-normal distribution has a different shape, where the logarithm of the variable is normally distributed; hence, it has a longer tail on one side rather than a symmetrical bell shape. The bimodal distribution features two different peaks, which creates a distinct shape that can indicate two different underlying groups or phenomena affecting the data. Lastly, the binomial distribution describes discrete outcomes typically associated with counting successes in a fixed number of trials, resulting in a shape that can vary significantly depending on the probability of success and the number of trials, but does not conform to the bell-shaped curve characteristic of the normal distribution.