# mean

(redirected from X-bar)
Also found in: Dictionary, Thesaurus, Medical, Legal, Encyclopedia.

## Mean

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.

## 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 ?
Figure 3 depicts the keyed dimension format with a plotting grid and with the data entry table and R chart below the X-bar chart.
Duncan[7] proposed an economic model for x-bar control charts in 1956.
On-Line Analyst for quality control provides X-bar, R, and sigma charts and generates C, U, P, NP, moving-average/moving-range, and individual charts.
An operator can see X-bar, R, capability, and Pareto charts right at the terminal.
And like its mold line counterpart, the software also has the capability to chart and print X-bar and R charts to provide a history of sand quality with each order.
Of these, the x-bar chart, r-chart, individual-x chart and moving-range chart are most frequently used in analysis for the reflow process.
X-Bar, R-Bar, and trend charts can be viewed on the screen simultaneously for all 20 variables chosen.
SPC-PC Version II software now includes routines for X-bar and R charts, X-bar and sigma charts, individuals and moving-range charts, moving average and range charts, histograms and process-capability charts, CuSum charts, multi-variate control charts, p and np charts, c and u charts, scatter plots, and pareto analysis.
Monitoring two parameters at once, it performs the usual statistical measures such as standard deviation and x-bar and R charts.
0001' and produce QC charts--histograms, X-bar, R, etc.
On its most controversial level, the Streamer1 package is based on the argument that common SPC analysis - the kind that revolves around x-bar and R-charts - doesn't work for injection molding.
Each PMA system offers a variety of statistical calculations and related displays, including histograms, x-bar and R-charts, Cpk, and limit determination.

Site: Follow: Share:
Open / Close
{"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0}