Final answer:
The Empirical Rule indicates that for a bell-shaped distribution, roughly 95 percent of data falls within two standard deviations of the mean.
Step-by-step explanation:
The Empirical Rule states that the approximate percentage of measurements in a data set that fall within two standard deviations of their mean, assuming the data set has a bell-shaped distribution, is approximately 95 percent.
For a normal distribution, which is symmetric, it's observed that:
- About 68 percent of the data falls within one standard deviation of the mean.
- About 95 percent of the data falls within two standard deviations of the mean.
- More than 99 percent of the data falls within three standard deviations of the mean.
This pattern is well-established in statistics and is crucial when analyzing data and predicting outcomes based on the normal probability distribution.