Difference between revisions of "Arithmetic mean"

m (Arithmetic Mean moved to Arithmetic mean: There's no need to capitalize "mean")
(Category statistics)
 
(6 intermediate revisions by 3 users not shown)
Line 1: Line 1:
=== Arithmetic Mean ===
+
The '''arithmetic mean''' of a [[set]] of numbers (or variables) is the sum of all the numbers, divided by the number of numbers - the [[average]] of the set. If we let <math>{AM}</math> denote Arithmetic Mean,
 +
<center><math>AM=\frac{x_1+x_2+\cdots+x_n}{n}</math></center>
 +
is the arithmetic mean of the <math>{n}</math> numbers <math>x_1,x_2,\ldots,x_n</math>.
  
The arithmetic mean of a set of numbers (or variables) is the sum of all the numbers, divided by the number of numbers. If we let <math>{AM}</math> denote Arithmetic Mean, <math>AM=\frac{x_1+x_2+\cdots+x_n}{n}</math> is the arithmetic mean of the <math>{n}</math> numbers <math>x_1,x_2,\ldots,x_n</math>.
+
For example, if I wanted to find the average of the numbers 3, 1, 4, 1, and 5, I would compute:
 +
<center><math> \frac{3+1+4+1+5}{5} = \frac{14}{5}.</math></center>  
  
(Umm how can you center an equation (\[ \])?)
 
  
For example, if I wanted to find the average of the numbers 3, 1, 4, 1, and 5, I would compute: <math> \frac{3+1+4+1+5}{5} = \frac{14}{5}</math>. Arithmetic means are also called averages. Arithmetic means show up frequently in contest problems.
+
 
 +
Arithmetic means show up frequently in contest problems, often in the [[AM-GM]] [[inequality]] or its variant, the [[RMS-AM-GM-HM]] inequality.
 +
 
 +
[[Category:Statistics]]

Latest revision as of 11:44, 20 September 2015

The arithmetic mean of a set of numbers (or variables) is the sum of all the numbers, divided by the number of numbers - the average of the set. If we let ${AM}$ denote Arithmetic Mean,

$AM=\frac{x_1+x_2+\cdots+x_n}{n}$

is the arithmetic mean of the ${n}$ numbers $x_1,x_2,\ldots,x_n$.

For example, if I wanted to find the average of the numbers 3, 1, 4, 1, and 5, I would compute:

$\frac{3+1+4+1+5}{5} = \frac{14}{5}.$


Arithmetic means show up frequently in contest problems, often in the AM-GM inequality or its variant, the RMS-AM-GM-HM inequality.