Remove duplication to calculate percentage

app/helpers/stats_helper.rb

@@ -30,9 +30,4 @@ module StatsHelper
     opt[:data][:graph] = admin_api_stats_path(budget_investments: true)
     content_tag :div, "", opt
   end
-
-  def calculate_percentage(fraction, total)
-    percent = fraction / total.to_f
-    percent.nan? ? 0.0 : (percent * 100).round(3)
-  end
 end

app/models/budget/stats.rb

@@ -188,11 +188,6 @@ class Budget::Stats
       calculate_percentage(participants, population)
     end
 
-    def calculate_percentage(fraction, total)
-      percent = fraction / total.to_f
-      percent.nan? ? 0.0 : (percent * 100).round(3)
-    end
-
     def supports(supportable)
       ActsAsVotable::Vote.where(votable_type: "Budget::Investment", votable_id: supportable.investments.pluck(:id))
     end

app/models/concerns/statisticable.rb

@@ -11,6 +11,13 @@ module Statisticable
     def generate
       self.class.stats_methods.map { |stat_name| [stat_name, send(stat_name)] }.to_h
     end
+
+    private
+
+      def calculate_percentage(fraction, total)
+        percent = fraction / total.to_f
+        percent.nan? ? 0.0 : (percent * 100).round(3)
+      end
   end
 
   class_methods do

app/models/poll/stats.rb

@@ -1,6 +1,5 @@
 class Poll::Stats
   include Statisticable
-  include StatsHelper
   alias_method :poll, :resource
 
   def self.stats_methods