Module 17: Background You’ll Need 3

  • Understand the difference between mean and median

Two Measures of Center—The Mean and the Median

  • The mean of a data set is also commonly known as the average of a data set.
  • The median of the data set is the value “in the middle” after all of the values have been arranged in ascending order.

Every year, bullfrogs compete in a jumping contest at the Calaveras County Jumping Frog Jubilee (a contest inspired by a short story by Mark Twain). One year, researchers recorded the jump distances of frogs entered in the contest.[1]

The following are the jump distances (in meters) for a sample of [latex]15[/latex] bullfrogs.

0.1 0.4 0.6 0.8 1.3 1.5 1.6 1.7
1.8 1.8 1.9 1.9 1.9 2.0 2.2  

The jump distances have been arranged in order from the shortest distance to the longest distance.


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  1. Astley, H. C., Abbott, E. M., Azizi, E., Marsh, R. L., & Roberts, T. J. (2013). Chasing maximal performance: A cautionary tale from the celebrated jumping frogs of Calaveras County. The Journal of Experimental Biology, 216(21), 3947–3953.