In a normally distributed dataset, what percentage of the sample lies within two standard deviations of the mean?

In a normally distributed dataset, the empirical rule, also known as the 68-95-99.7 rule, states that approximately 95% of the data falls within two standard deviations of the mean. This characteristic of the normal distribution reflects how data is spread around the mean, indicating that as you move further from the mean (in this case, beyond two standard deviations), you encounter progressively fewer data points.

This rule essentially highlights that a majority of observations (95%) will be found within this range, illustrating the significance of the mean and standard deviation as metrics for understanding data distribution in statistical analysis. Therefore, choosing the percentage that corresponds to the two standard deviation range effectively encapsulates a fundamental aspect of normal distribution, making it the correct choice for this question.