68-95-99.7 Rule
Definition
The 68-95-99.7 Rule describes how data is distributed in a normal distribution. It states that approximately 68% of the data falls within one standard deviation, 95% within two standard deviations, and 99.7% within three standard deviations from the mean.
5 Must Know Facts For Your Next Test
- Approximately 68% of the data in a normal distribution lies within one standard deviation from the mean.
- Around 95% of the data in a normal distribution is found within two standard deviations from the mean.
- About 99.7% of the data in a normal distribution falls within three standard deviations from the mean.
- The rule helps to quickly estimate probabilities and understand the spread of data in a normal distribution.
- It is also known as the Empirical Rule or the Three-Sigma Rule.
Review Questions
- What percentage of data lies within two standard deviations in a normal distribution?
- How does the Empirical Rule relate to standard deviations?
- What are other names for the 68-95-99.7 Rule?
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Related terms
Standard Deviation: A measure of how spread out numbers are around the mean of a dataset.
Normal Distribution: A probability distribution that is symmetric about its mean, showing that data near the mean are more frequent in occurrence than data far from it.
Mean: The average value of a set of numbers, calculated by dividing their sum by their quantity.
