hw 5.2

Author: pfryga

Diff for: hw5.2/README.md

@@ -32,9 +32,37 @@ mongoimport -d test -c zips --drop small_zips.json
 ### Response
 
 ````
-
+db.zips.aggregate([
+    {
+        $match: { state: {
+            $in: ['CA', 'NY'] }
+        }
+    },
+    {
+        $group: {
+            _id: {
+                state: '$state',
+                city: '$city'
+            },
+            pop: {
+                $sum: '$pop'
+            }
+        }
+    },
+    {
+        $match: { pop: { $gt: 25000 }}
+    },
+    {
+        $group: {
+            _id: null,
+            average: {
+                $avg: '$pop'
+            }
+        }
+    }
+])
 ````
 
-*
+* 44805 (44804.782609)