Database
[{Avg_Rating:3.6,Num_Votes:1999},{Avg_Rating:3.8,Num_Votes:1699},{Avg_Rating:4.5,Num_Votes:2599},{Avg_Rating:4.7,Num_Votes:134},{Avg_Rating:5,Num_Votes:2340}]
Query
db.collection.aggregate([{$match:{Num_Votes:{$gt:1000}}},{$group:{_id:{$floor:"$Avg_Rating"},Num_Movies:{$sum:"$Num_Votes"}}}])