Variance and Covariance: How Much Money Do Baseball Players Really Make? (MSTE)
Library Home 
Full Table of Contents 
Library Help
http://www.mste.uiuc.edu/malcz/spreads/intro.html  


Ed Malczewski; University of Illinois at UrbanaChampaign (UIUC)  
An exploration of idea of variance and how it is used in statistics. The average (mean) salary of a ballplayer in the majors leagues is $1.2 million dollars. Given only this fact, it is easy to see how the perception of the overpaid baseball player was created. However, it is often conveniently ignored that the median salary for major leaguers is only $410,000  50% make more than $410,000, but 50% make less. Are the salaries for the majority of baseball players consistent with the public belief that they make too much money? Another statistic that can help us answer this question is called the variance: a measure of the spread of data. A Sketchpad sketch and an Excel file may be downloaded.  


Levels:  High School (912) 
Languages:  English 
Resource Types:  Lesson Plans and Activities, InternetBased Projects, Documents/Sketches/Galleries, General Software Miscellaneous, Geometer's Sketchpad 
Math Topics:  Graphing of Data, Data Sets, Statistics 
[Privacy Policy] [Terms of Use]
© 1994 The Math Forum at NCTM. All rights reserved.
http://mathforum.org/