Which distribution is characterized by a bell-shaped curve?

The distribution characterized by a bell-shaped curve is known as the normal distribution. This type of distribution is symmetric around its mean, meaning that most of the data points cluster around this central value, with frequencies tapering off equally in both directions as you move away from the mean.

In a normal distribution, approximately 68% of the data falls within one standard deviation of the mean, about 95% within two standard deviations, and around 99.7% within three standard deviations. This predictable pattern in the data makes the normal distribution a key concept in statistics, often serving as a basis for various statistical tests and methodologies.

In contrast, positive and negative skew distributions do not follow this bell-shaped pattern. A positive skew has a longer tail on the right side, indicating that there are a number of higher values that distort the mean to be greater than the median. Similarly, a negative skew features a longer tail on the left side, where lower values pull the mean down compared to the median. Bimodal distribution refers to a distribution with two different modes, indicating the presence of two peaks, rather than a single peak typical of the normal distribution.