Planning
Lab 2
Hank Feild
05-Aug-2014

Overview:

This program calculates the total bill of grocery purchases, including tax.


Requirements:

    - no input from the user
    - sets a tax rate and a the prices for a variety of grocery items
    - calculates and outputs:
      * price per item
      * the total of all items
      * the tax on the items
      * the grand total


Use cases:

    - With a tax rate of 0 and one item, milk ($2.50), the output would be:
        Milk: $2.50 
        Total: $2.50
        Tax: $0.00
        Grand total: $2.50

    - With a tax rate of 5% and two items (milk $2.50 and bread $1.00), the
      output would be:
        Milk: $2.50
        Bread: $1.00
        Total: $3.50
        Tax: $0.18
        Grand total: $3.68


Pseudo code:

    1. Set the tax rate (constant: TAX_RATE).
    2. Set the variables milkPrice, breadPrice, and eggsPrice.
    3. Declare tax and total.
    4. Print out the bought items and their prices.
    5. Calculate the total and tax and print them out.
        - pre-tax total = milkPrice + breadPrice + eggsPrice
        - tax = pre-tax total * TAX_RATE
        - final total = pre-tax total + tax