When sample sizes are equal, in other words, there could be five values in each sample, or n values in each sample. The grand mean is the same as the mean of sample means.
· NN = Total number of sets.
· ∑x∑x = sum of the mean of all sets.
Determine the mean of each group or set’s samples. Use the following data as a sample to determine the mean and grand mean.
Step 1: Compute all means
Step 2: Divide the total by the number of groups to determine the grand mean. In the sample, there are three groups.