What percentage of data lies within ±2 standard deviations from the mean?

The correct answer indicates that approximately 95% of the data lies within ±2 standard deviations from the mean in a normal distribution. This concept is derived from the empirical rule, also known as the 68-95-99.7 rule, which provides a quick reference to understanding how data is distributed in a bell-shaped curve.

According to this rule, roughly 68% of data falls within one standard deviation of the mean, 95% falls within two standard deviations, and 99.7% falls within three standard deviations. Therefore, when considering a range of ±2 standard deviations, you capture the vast majority of the data points, which aligns with this statistical principle. Understanding this distribution is crucial for interpreting statistical data and making informed decisions based on that data in various fields, including laboratory management.