input: 
  def determine_commission_rate(gross_sales: float) -> float:
      """Determine the commission rate based on the gross sales amount.
      The commission rates are as follows:
      - 10% if gross sales are $10,000 or more
      - 7% if gross sales are between $5,000 and $10,000 (inclusive)
      - 5% if gross sales are less than $5,000
      
      >>> determine_commission_rate(15000)
      0.1
      >>> determine_commission_rate(7500)
      0.07
      >>> determine_commission_rate(4000)
      0.05
      """
  
output:     if gross_sales >= 10000:
          return 0.1
      elif gross_sales >= 5000:
          return 0.07
      else:
          return 0.05