The mean difference (more correctly, ‘difference in means’) is a standard statistic that measures the absolute difference between the mean value in two groups in a clinical trial. It estimates the amount by which the experimental intervention changes the outcome on average compared with the control.

Formula

Mean Difference=∑x1n−∑x2nMean Difference=∑x1n−∑x2n

Where −

·        x1x1 = Mean of group one

·        x2x2 = Mean of group two

·        nn = Sample size

Example

Problem Statement:

There are 2 dance groups whose data is listed below. Find the mean difference between these dance groups.

Solution:

∑x1=3+9+5+7=24∑x2=5+3+4+4=16M1=∑x1n=244=6M2=∑x2n=164=4MeanDifference=6−4=2