Easy is related to Level. Level is related to Amount. Amount is related to Population. 
Installation is related to Camp. Camp is related to Cabin. Cabin is related to Room. Room is a type of Opportunity. 
Easy <--RelatedTo--> Level <--RelatedTo--> Amount <--RelatedTo--> Population 
Installation <--RelatedTo--> Camp <--RelatedTo--> Cabin <--RelatedTo--> Room --IsA--> Opportunity 