The Empirical Rule, sometimes called the 68-95-99.7 rule, states that for a given dataset with a normal distribution:
68% of data values fall within one standard deviation of the mean.
95% of data values fall within two standard deviations of the mean.
99.7% of data values fall within three standard deviations of the mean.
Test your knowledge of the Empirical Rule using the practice problems below.
The height of plants in a certain garden are normally distributed with a mean of 12.3 inches and a standard deviation of 4.1 inches.
Use the Empirical Rule to estimate what percentage of plants are between 8.2 and 16.4 inches tall.