What is the standard deviation percentage for data in a normal distribution that falls within 3 standard deviations?

In a normal distribution, the empirical rule, also known as the 68-95-99.7 rule, describes how data is distributed in relation to the mean and standard deviations. According to this rule, approximately 68% of the data falls within one standard deviation from the mean, around 95% falls within two standard deviations, and about 99.7% falls within three standard deviations.

This means that when considering a range of data within three standard deviations from the mean, you can expect that nearly all of the values will fall into this category, reflecting a high level of confidence in capturing the majority of the distribution. The choice indicating 99.7% is the one that correctly represents this statistical concept, illustrating that nearly all data in a normal distribution is encompassed within that range. This property of the normal distribution is foundational in statistics and is widely applicable in various fields for data analysis and interpretation.