Information AboutStatistic |
| CATEGORIES ABOUT STATISTIC | |
| statistical theory | |
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A statistic (singular) is the result of applying a Function (statistical Algorithm ) to a Set Of Data . More formally, statistical theory defines a statistic as a function of a Sample where the function itself is independent of the sample's distribution. EXAMPLES In the calculation of the Arithmetic Mean , for example, the algorithm consists of summing all the Data values and dividing this sum by the number of data items. Thus the arithmetic mean is a statistic. Other examples of statistics include
PROPERTIES Observability A statistic is an ''observable'' Random Variable , which differentiates it from a ''parameter'', an unobservable quantity describing a property of a Statistical Population . Statisticians often contemplate a parameterized family of Probability Distribution s, any member of which could be the distribution of some measurable aspect of each member of a population, from which a sample is drawn randomly. For example, the parameter may be the average height of 25-year-old men in North America. The height of the members of a sample of 100 such men are measured; the average of those 100 numbers is a statistic. The average of the heights of all members of the population is not a statistic unless that has somehow also been ascertained. The average height of ''all'' (in the sense of ''genetically possible'') 25-year-old North American men is a ''parameter'' and not a statistic. Statistical properties Important potential properties of statistics are Completeness , Sufficiency and Unbiased ness. SEE ALSO |
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