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The expected value of a random variable. Arithmetic average of a sample.

Arithmetic Mean Average

An average calculated by adding the value of the points in a data set and dividing the sum by the number of data points. For example, suppose one wishes to calculate the average income of a country with exactly five people in it, and their incomes are $25,000, $26,000, $43,000, $70,000, and $72,000. It is calculated as:

($25,000 + $26,000 + $43,000 + $70,000 + $72,000) / 5 = $47,200.

A limitation to the arithmetic mean average is that it can be overly affected by extremes in either direction. For example, if one of the five persons in the country earns $100 billion per year, the arithmetic mean average income would be in the billions and would not accurately count the other four citizens. For this reason, many analysts use the median in conjunction with the arithmetic mean average. The arithmetic mean average is also called simply the mean.


The average of a set of numbers.Contrast with median,which is the middle figure in a set of numbers,and mode,which is the value that appears most often in a set of numbers.

Example: A survey of home values in a neighborhood of nine houses obtained the following values:

The mean, or average, is the total of all values divided by 9, or $143,044.The median is the middle number when the numbers are all arranged from highest to lowest,which would be house 5, or $139,850.The mode is $139,000,because it is the number that appears most often.

References in periodicals archive ?
For the other growth measures, percentages of first and second place rankings were 2 percent for the standard base, 12 percent for the reverse base, 13 percent for the average of the standard and reverse bases, and 17 percent for the geometric mean.
coli levels greater than 1,000 CFU/100 mL, as they were equated to 10 CFU/100 mL and 1,000 CFU/100 mL, respectively, for ease of geometric mean calculations.
Unfortunately, these properties do not result in a unique definition for the geometric mean of a general number of matrices.
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Incorporating a Geometric Mean Formula into the CPI.
16) It long predates the BLS decision to switch to a geometric mean formula for computing most of the basic CPIs.
7) Let us consider the weighted geometric mean of unequal positive numbers a & b; G(a, b; p, q) = [a.
Geometric mean increased linearly as the amount of chopped alfalfa in the TMR decreased but standard deviation was increased as geometric mean decreased (p<0.
Geometric mean copper concentrations directly under the drip line of the viewing platform reached a maximum of 52 mg/kg 60 months after construction but declined to 41 mg/kg after 131 months.
Males were older than females (male geometric mean age: 38 months, 95% CI = 26 - 54, n = 23; females: 18 months, 95% CI = 10-33, n= 12; t=2.
They cover statistical selection rationale, sampling recreational waters, the lognormal distribution and the use of the geometric mean and arithmetic mean in measurement, microbial risk assessment modeling, models for concentration-response relationships, "nowcasting," and statistical sensitivity analysis.

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