# How to Calculate a Sample Size in SPSS?

Sample sizes are needed in statistics because it isn't always possible to conduct an analysis of an entire population. For example, if you want to know the average height of a beech tree, it would ...
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http://www.ehow.com/how_7350336_calculate-sample-size-spss.html

## How to Calculate Z-Scores With the SPSS Student Version?

A z-score is a descriptive statistic used to determine how common or extreme a given score is by determining its distance from the mean in standard deviation units. Z-scores are calculated by subtr...
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http://www.ehow.com/how_7328842_calculate-z_scores-spss-student-version.html

## How to Calculate Probability With One Sample?

The science of probability deals with calculating how likely certain events are to occur. Probability calculations can get complicated, and are sometimes completely unintuitive. But the basic calcu...
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http://www.ehow.com/how_8290211_calculate-probability-one-sample.html

## How to Calculate Variance of a Sample?

In statistics, different values derived from a sample set have significant meanings. One of those values is the variance, which measures the spread of the sample. Other important values like the st...
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http://www.ehow.com/how_8054971_calculate-variance-sample.html

## What is a valid sample size?

A valid sample size is the number required to project results from the sample on to a population, accurately. For instance, if Anne gets 3 "A"s and 1 "B" in her classes, you might want to estimate,...
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http://www.answerbag.com/q_view/2206289