The rule sometimes called the Empirical Rule, which means "based on observations" The graph is shown this way : (see attachment). This rule is represented by a<span><span>bout 68% of values fall within one standard deviation of the mean.</span>About 95% of the values fall within two standard deviations from the mean.<span>Almost all of the values — about 99.7% — fall within three standard deviations from the mean.</span></span>
