input: 
  def determine_commission_rate(gross_sales):
      if gross_sales >= 10000:
          return 0.1
      elif gross_sales >= 5000:
          return 0.07
      else:
          return 0.05
  
  # Testing the function
  # Examples:
  # >>> determine_commission_rate(12000)
  # 0.1
  # >>> determine_commission_rate(7500)
  # 0.07
  # >>> determine_commission_rate(2500)
  # 0.05
  
output:     if gross_sales >= 10000:
          return 0.1
      elif gross_sales >= 5000:
          return 0.07
      else:
          return 0.05