In a normal distribution, what percentage of data falls within one standard deviation of the mean?

In a normal distribution, approximately 68% of the data falls within one standard deviation of the mean. This is a key characteristic of the normal distribution, often referred to as the empirical rule or the 68-95-99.7 rule. The mean serves as the center of the distribution, and one standard deviation encompasses a significant portion of the data.

This concept is fundamental in statistics because it illustrates how data values are spread around the mean in a way that most of the observations lie close to the average. Specifically, within one standard deviation, the probability of finding data points is considerably high, which reflects the nature of the normal distribution—symmetrical and bell-shaped. Understanding this helps in various applications such as hypothesis testing and confidence intervals in statistics.