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Statistical Advisor, How To Compare Two Variables

Use one of the following:

BASIC STATISTICS: That chapter discusses the so-called t-test for dependent samples, which compares the means of two variables or measurements. The test assumes that the data in the two variables are normally distributed. If the resultant t-value is statistically significant, then one can conclude that the means in the two variables are different.

NONPARAMETRICS & DISTRIBUTIONS: That chapter discusses several so-called nonparametric tests for comparing variables. These test should be used if one is not sure of the distribution of the variables used in the comparison. For example, the data may actually consist of rankings rather than precise measurements.

GRAPHICAL ANALYTIC TECHNIQUES: Graphical analytic techniues include numerous facilities for producing histograms, line graphs, scatterplots, etc., simultaneously for more than one variable. These graphs offer a wide variety of methods to visualize differences between variables.