What is Analysis of Variance with example?

Analysis of Variance (ANOVA) is a statistical technique used to determine whether there are any significant differences between two or more groups of data. It is a method for comparing the means of different groups and can be used to test hypotheses about the effects of one or more independent variables on a dependent variable.

Here’s an example of how ANOVA can be used in practice:

Suppose a manufacturer wants to test the effectiveness of three different types of fertilizers (A, B, and C) on the growth of a particular crop. The manufacturer sets up three plots of land and applies one type of fertilizer to each plot. After a certain amount of time has passed, the manufacturer measures the height of the crop in each plot.

The data can be organized into a table as follows:

FertilizerPlot 1Plot 2Plot 3

To determine whether there is a significant difference in crop height between the three types of fertilizer, we can use ANOVA. In this case, the independent variable is the type of fertilizer (A, B, or C), and the dependent variable is the height of the crop.

The ANOVA test will calculate a statistic called the F-ratio, which represents the ratio of the variance between the groups to the variance within the groups. If the F-ratio is large enough, it indicates that there is a significant difference between at least two of the groups.

In this example, the ANOVA test might produce an F-ratio of 6.47 with a p-value of 0.02. This would indicate that there is a significant difference in crop height between the three types of fertilizer.

Based on this result, the manufacturer could conclude that one type of fertilizer is more effective than the others and adjust their production accordingly.