In a normal distribution, what percentage of data lies within 1 standard deviation from the mean?

In a normal distribution, the empirical rule states that approximately 68% of the data lies within one standard deviation of the mean. This rule is foundational in statistics because it describes how data is distributed in a bell-shaped curve.

When considering a normally distributed dataset, if you calculate the mean and then go one standard deviation above and below that mean, you will find that the vast majority of values—specifically about 68%—will fall within that range. This characteristic is crucial for making inferences about the population based on sample data and for understanding variability and the probability of different outcomes in a given distribution.

Understanding this concept is vital for practitioners in fields that rely on data-driven decision-making, as it provides insights into how likely certain outcomes are based on the spread of the data within standard deviations. This knowledge is particularly useful when interpreting data, making predictions, or conducting statistical analysis.