Clustering is done based on houses data and say suppose cluster 1 contains 5 houses. Appliance 1 is used in 2 houses out of 5 and appliance 2 is used in 4 out of 5 houses.Each appliance produces an error . Need to find sum of the errors of each appliance in each cluster. Summing up of errors at appliance level would not give us the correct picture as appliance 1 is used in 2houses but appliance 2 is used in 4houses. How do we handle such data? How we get the total errors produced from each appliance for a particular cluster?