Charge is related to Electrical. Electrical is related to Lamp. Lamp is related to Living. Living is related to Eat. 
Margin is a type of Amount. Amount is related to Whole. 
Charge <--RelatedTo--> Electrical <--RelatedTo--> Lamp <--RelatedTo--> Living <--RelatedTo--> Eat 
Margin --IsA--> Amount <--RelatedTo--> Whole 