casting total as float in the presenter's calculate percent method

analytics_dashboard/courses/presenters.py

@@ -314,11 +314,10 @@ def _build_binned_ages(self, api_response):
         return binned_ages
 
     def _calculate_total_enrollment(self, api_response):
-        # get the sum as a float so we can divide by it to get a percent
-        return float(sum([datum['count'] for datum in api_response]))
+        return sum([datum['count'] for datum in api_response])
 
     def _calculate_percent(self, count, total):
-        return count / total if total > 0 else 0.0
+        return count / float(total) if total > 0 else 0.0
 
     def _calculate_education_percent(self, api_response, levels, total):
         """ Aggregates levels of education and returns the percent of the total. """