Following along with the live coding video was extremely helpful.

transform.py

@@ -6,11 +6,23 @@
 
 def maximum(data):
     "Returns the largest number in data"
-    raise NotImplementedError
+    highest = None
+    for number in data:
+        if highest is None:
+            highest = number
+        if number > highest:
+            highest = number
+    return highest
 
 def minimum(data):
     "Returns the smallest number in data"
-    raise NotImplementedError
+    lowest = None
+    for number in data:
+        if lowest is None:
+            lowest = number
+        if number < lowest:
+            lowest = number
+    return lowest
 
 def bounds(data):
     "Returns a list of the smallest and largest numbers in data"