http://www.ck12.org Chapter 6. Normal Distribution Curves
6.5 Empirical Rule
Here you’ll learn how to represent the standard deviation of a normal distribution on a bell curve. Then you’ll use
the Empirical Rule to solve normal distribution problems.
Suppose you know that 350 babies were born at Neo Hospital in the past 6 months. The average weight for the
babies was found to be 6.8 lbs, with a standard deviation of 0.5 lbs. How many babies would you expect to weigh
more than 7.3 lbs? How many babies would you expect to weigh more than 7.8 lbs? How many babies would you
expect to weigh between 6.3 and 7.8 lbs? By the end of this Concept you’ll be able to find these answers.
Watch This
First watch this video to learn about the Empirical Rule.
MEDIA
Click image to the left for more content.CK-12 Foundation: Chapter6EmpiricalRuleA
Then watch this video to see some examples.
MEDIA
Click image to the left for more content.CK-12 Foundation: Chapter6EmpiricalRuleB
Watch this video for more help.
MEDIA
Click image to the left for more content.Khan Academy ck12.org Normal Distribution Problems: Empirical Rule
Guidance
You have already learned that 68% of the data in a normal distribution lies within 1 standard deviation of the mean,
95% of the data lies within 2 standard deviations of the mean, and 99.7% of the data lies within 3 standard deviations