Difference between revisions of "Average"
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If equal weights are hung from a ruler, and the weight of the ruler itself is small enough to be neglected, the distance marking at which the ruler will balance can be shown to be the average of the distance markings at which the weights are hung. | If equal weights are hung from a ruler, and the weight of the ruler itself is small enough to be neglected, the distance marking at which the ruler will balance can be shown to be the average of the distance markings at which the weights are hung. | ||
| − | In this diagram, weights are hung at the 1, 9, and 11 inch marks. The average of 1, 9, and 11 is 7. The ruler will balance if it | + | In this diagram, weights are hung at the 1, 9, and 11 inch marks. The average of 1, 9, and 11 is 7. The ruler will balance if it is hung at the 7 inch mark. This can be considered as an example of an "analog computer" for the average. |
[[category:Mathematics]] | [[category:Mathematics]] | ||
Revision as of 02:37, May 15, 2007
Average is the sum of a group of numbers divided by the number of values in the group. For example, the average of 3, 5, and 7 is .
Another term for average is the arithmetic mean.
The other two common types of average are the median and the mode.
- The median is the value which splits the group of numbers in the middle: half are higher, half are lower.
- The mode is the most common number.
An "analog computer" for the average
If equal weights are hung from a ruler, and the weight of the ruler itself is small enough to be neglected, the distance marking at which the ruler will balance can be shown to be the average of the distance markings at which the weights are hung.
In this diagram, weights are hung at the 1, 9, and 11 inch marks. The average of 1, 9, and 11 is 7. The ruler will balance if it is hung at the 7 inch mark. This can be considered as an example of an "analog computer" for the average.