Ответ:

products = {

   "product1": {"weight": 2.5, "total_cost": 9.0},

   "product2": {"weight": 3.0, "total_cost": 10.5},

   "product3": {"weight": 1.0, "total_cost": 5.0}

}

product_name = input("Enter the name of the product: ")

if product_name in products:

   product = products[product_name]

   cost_per_kg = product["total_cost"] / product["weight"]

   print("The cost of 1 kg of {} is {:.2f}".format(product_name, cost_per_kg))

else:

   print("The entered product name is not valid.")

Объяснение: