Home... Home on the Range


In order to get a better idea of how a given data point relates to other data, it is important to get an idea of how spread out the data are. One way of doing this is by using the range.

The range is the distance between the highest and lowest data points in a set. For instance:

The NATIONAL WEATHER SERVICE O'HARE AIRPORT (Chicago, IL) reported the following temperature information for June 15, 1996.


Temperature Information for Chicago (in degrees Fahrenheit)
Mean Temperature71
High Temperature84
Low Temperature57


Knowing this information, how would you dress for the day? 71 degrees is a fairly comfortable mean temperature, but 57 can be a little on the chilly side and 84 is a little warm. So, can you see how it is important to know more than just the mean of a data set?

On this day, there was a range of 27 degrees Fahrenheit. The highest point was 84 and the lowest was 57. Thus, the range is found by subtracting 57 from 84.

Check out the NATIONAL WEATHER SERVICE O'HARE AIRPORT (Chicago, IL) for up-to-date weather information and find out yesterday's range of temperatures.

Get out your dice scores and continue to the next page to learn about another measure of spreads.



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