Question

The data represented by the graph is normally distributed and adheres to the 68-95-99.7 rule. The standard deviation of this data is , and % of the data is either less than 4.2 or more than 11.4.

Answer 1

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 about 68% of values fall within one standard deviation of the mean.About 95% of the values fall within two standard deviations from the mean.Almost all of the values — about 99.7% — fall within three standard deviations from the mean.