Introductory Statistics

# Key Terms

Analysis of Variance
also referred to as ANOVA, is a method of testing whether or not the means of three or more populations are equal. The method is applicable if:
• all populations of interest are normally distributed.
• the populations have equal standard deviations.
• samples (not necessarily of the same size) are randomly and independently selected from each population.

The test statistic for analysis of variance is the F-ratio.

One-Way ANOVA
a method of testing whether or not the means of three or more populations are equal; the method is applicable if:
• all populations of interest are normally distributed.
• the populations have equal standard deviations.
• samples (not necessarily of the same size) are randomly and independently selected from each population.
• there is one independent variable and one dependent variable.

The test statistic for analysis of variance is the F-ratio.

Variance
mean of the squared deviations from the mean; the square of the standard deviation. For a set of data, a deviation can be represented as x$x ¯ x ¯$ where x is a value of the data and $x ¯ x ¯$ is the sample mean. The sample variance is equal to the sum of the squares of the deviations divided by the difference of the sample size and one.