Final answer:
The mu +- a few sigma rule, also known as the Empirical Rule or the 68-95-99.7 rule, is a statistical rule that applies to bell-shaped distributions.
Step-by-step explanation:
The mu +- a few sigma rule, also known as the Empirical Rule or the 68-95-99.7 rule, is a statistical rule that applies to bell-shaped distributions. It states that:
About 68 percent of the values lie within one standard deviation of the mean.
About 95 percent of the values lie within two standard deviations of the mean.
About 99.7 percent of the values lie within three standard deviations of the mean.
This rule can be used to estimate the range of values that are likely to occur in a normal distribution.