# Measuring Variability for Symmetrical Distributions

##### This Measuring Variability for Symmetrical Distributions assessment also includes:

How do we measure the deviation of data points from the mean? An enriching activity walks your class through the steps to calculate the standard deviation. Guiding questions connect the steps to the context, so the process is not about calculating a number with no meaning. Questioning techniques also ensure the class has an understanding of the concept of standard deviation.

CCSS: Designed

##### Instructional Ideas

• After calculating the standard deviation using the method provided, use a calculator and discuss why there might be a difference in the answers
• Have the class develop a method, such as a pneumonic device, to help remember the formula for the standard deviation
##### Classroom Considerations

• The fifth lesson in a 20-lesson module
##### Pros

• Includes talking points for the closing discussion
• Provides an explanation of why n-1 is used in the formula and not just n

• None