Understanding The Measure of Center

Mean, Median, and Mode

Formative Assessment

Summary of the Math: Mean, Median, and Mode

Read and Discuss

  • Measures of Center
    • Mean: A measure of center in a set of numerical data, computed by adding the values in a list and then dividing by the number of values in the list.
    • Median: A measure of center in a set of numerical data. The median of a list of values is the value appearing at the center of a sorted version of the list—or the mean of the two central values, if the list contains an even number of values.
    • Mode: A measure of center that occurs the most often in a data set.
  • Measures of Spread
    • Range: The difference between the extreme (least and greatest) values in a data set.
    • Mean Absolute Deviation: A measure of variation in a set of numerical data, computed by adding the distances between each data value and the mean, then dividing by the number of data values.
  • Outlier: A data value that is far from the rest of the data.

Hint:

Can you:

  • Explain how the different measures of center are affected when data values are added or moved?
  • Understand why the median and mean of a data set do not have to be data values, but why the mode, if it exists, will always be a data value?
  • Describe or give an example of a data set for which the median is a better measure of what is typical than the mean?