Outliers and Skewed Data

Warm Up Find the mean, median, mode and range of the following data: 3, 4, 5, 3, 5, 7, 9, 3, 8

Objective The student will be able to identify outliers and how they affect data sets.

Exploration Matapeake Middle School Basketball Team Spreadsheet.

Standard Deviation Standard Deviation is a measure of how spread the set of numbers are in a data set. Things needed to calculate standard deviation: Mean Variance These are used to then calculate the standard deviation

With a Partner Find the Outlier of the Data and Determine how it will Skew the Data: 1, 100, 2, 5, 3, 7, 3, 6, 10

Outliers and Skewed Data Outliers are pieces of data that “don’t” fit within the data set. They are either too large or too small. Data has a shape to its graph and outliers can affect the shape of their graph.

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With a Partner: Determine How the data is skewed:

Variance and Standard Deviation: The average squared differences from the mean Standard Deviation: Is the square root of the Variance Uses the lower case Greek letter Sigma:

Example

Continued… Find the Mean: Calculate the difference between each height and the mean.

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Continued… Calculate Variance:

Continued… Calculate the Standard Deviation: The square root of the Variance

With A partner… Find the standard deviation of the following: 2, 3, 4, 2, 4, 3, 4

Exit ticket and Homework What does a negatively skewed graph look like? Homework: Worksheet.