In this Excel tutorial you learn how to prepare anova three factor analysis in Excel.
ANOVA (Analysis of Variance) is a statistical method used to compare the means of two or more groups of data. In Excel, you can perform a three-factor ANOVA using the built-in ANOVA function.
Here are the steps to perform a three-factor ANOVA in Excel:
Enter your data into an Excel spreadsheet, with each column representing a factor and each row representing an observation.
Calculate the mean for each group in your data set. You can do this using the AVERAGE function in Excel.
Calculate the total sum of squares (SST) for each factor. To calculate the SST for each factor, use the following formula: =SUM((AVERAGE(range)-AVERAGE(data))^2). Replace "range" with the range of cells that contains the data for that factor, and "data" with the entire range of data.
Calculate the sum of squares between groups (SSB) for each factor. To calculate the SSB for each factor, use the following formula: =SUM(count*(AVERAGE(range)-AVERAGE(data))^2). Replace "count" with the number of observations in each group, "range" with the range of cells that contains the data for that factor, and "data" with the entire range of data.
Calculate the sum of squares within groups (SSW). To calculate the SSW, use the following formula: =SUMSQ(range)-SUM(range)^2/COUNT(range)). Replace "range" with the entire range of data.
Calculate the degrees of freedom (df) for each factor and for the error term. The df for each factor is the number of groups minus one. The df for the error term is the total number of observations minus the total number of groups.
Calculate the mean square for each factor and for the error term. To calculate the mean square, divide the sum of squares by the degrees of freedom.
Calculate the F-statistic for each factor. To calculate the F-statistic, divide the mean square for the factor by the mean square for the error term.
Use the ANOVA function in Excel to calculate the p-value for each factor. To do this, select a blank cell in your spreadsheet, type "=ANOVA(range,group1,group2,group3)", and press Enter. Replace "range" with the entire range of data, and "group1", "group2", and "group3" with the range of cells that contains the data for each factor.
Interpret the results. If the p-value for a factor is less than the significance level (usually 0.05), then there is strong evidence that the means of the groups are different.