Q:

# What is the difference between a parameter and a statistic?

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A statistic describes a sample, while a parameter describes an entire population. A sample is a smaller subset that is representative of a larger population.

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Credit: InteL Free Press CC-BY-SA 2.0

The symbols differ when reporting statistics versus parameters. The average symbol for a statistic is an x with a line on top of it. For a parameter, the average is represented by the symbol μ. Since it is not always possible to collect every single observation in a population, sampling procedures are used to select a representative sample. Random sampling allows a statistician to calculate statistics about a sample and apply them to a population.

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## Related Questions

• A:

A good statistical sample size is at least 100, and preferably more, participants. With a 100-participant sample size, the researcher has a margin of error of approximately 10 percent with a 95 percent confidence rating in the results. For the researcher to increase his confidence rating and reduce his margin of error he has to increase the size of the sample.

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• A:

The formula to find a sample variance is as follows: s squared equals sigma(x-x-bar)squared over n-1. Working out the problem involves determining the mean, subtracting the mean for each number and then squaring the result and then determining the average of the squared differences.

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• A:

To calculate simple variance, also called sample variance, start by calculating the mean of the set of numbers. Next, subtract the mean and square the result for each number. Finally, add the squared results, and divide this sum by one less than the number of data points.