Ballpark order challenge. What's the problem???

Question

Please, help. What's wrong with the code??? The test fails, although answers in first two tests are the same.

Items = {"nachos": 6.00, "pizza": 6.00, "cheeseburger": 10.00, "water": 4.00, "coke": 5.00}
Sum = 0
Order = input().lower().split()
for a in Order:
if a in Items:
i=Items.get(a)
else:
i = 5.00
Sum=Sum+i
print(Sum*1.07)

Challenge: You and three friends go to a baseball game and you offer to go to the concession stand for everyone. They each order one thing, and you do as well. Nachos and Pizza both cost $6.00. A Cheeseburger meal costs $10. Water is $4.00 and Coke is $5.00. Tax is 7%.

Task
Determine the total cost of ordering four items from the concession stand. If one of your friend’s orders something that isn't on the menu, you will order a Coke for them instead.

Input Format
You are given a string of the four items that you've been asked to order that are separated by spaces.

Output Format
You will output a number of the total cost of the food and drinks.

Answer 1

The "Sum" should be rounded to two decimals.

Answer 2

Thaaaanks 🤩🤩🤩