Question

Draw hierarchy charts or flowcharts that depict the programs described below. (See Appendix D for instructions on creating flowcharts.) Sales Tax Design a hierarchy chart or flowchart for a program that calculates the total of a retail sale. The program should ask the user for: \- The retail price of the item being purchased \(-\) The sales tax rate Once these items have been entered, the program should calculate and display: \- The sales tax for the purchase \(-\) The total of the sale

Short answer

Question: Create a hierarchy chart or a flowchart for a program that calculates the total of a retail sale, including the steps for asking the user for the retail price and sales tax rate, calculating the sales tax and total sale, and displaying the sales tax and total sale.

Step-by-step solution

Start Program

Begin the flowchart with a "Start" symbol to indicate the beginning of the program.

Input Retail Price

From the "Start" symbol, draw an arrow and connect it to an Input symbol. This symbol represents getting the retail price input from the user. Write "Enter retail price" in this symbol to specify the input we are asking from the user.

Input Sales Tax Rate

From the Input symbol of the retail price, draw an arrow and connect it to another Input symbol representing the sales tax rate. Write "Enter sales tax rate" in this symbol to specify the input we are asking from the user.

Calculate Sales Tax

Draw an arrow from the Input sales tax rate symbol to a Process symbol. In this process, we will calculate the sales tax using the formula: Sales tax = (Retail Price * Sales Tax Rate). Write "Calculate Sales Tax" inside the process symbol.

Calculate the Total Sale

Draw an arrow from the Process symbol used to calculate the sales tax to another Process symbol representing the total sale calculation. In this process, we will calculate the total sale using the formula: Total Sale = Retail Price + Sales Tax. Write "Calculate Total Sale" inside this process symbol.

Display Sales Tax and Total Sale

Draw an arrow from the Process used to calculate the total sale to an Output symbol. Write "Display Sales Tax and Total Sale" inside this symbol to specify that we need to display both values the user after the calculations are done.

End Program

Finally, draw an arrow from the Output symbol to the "End" symbol, signifying the completion of the program. Now you have a complete flowchart to represent the program that calculates the total of a retail sale.

Key concepts

Hierarchy Chart Design

When it comes to organizing and planning a program for calculating sales tax and the total of a retail sale, a hierarchy chart is an essential tool for a clear visualization of the program structure. A hierarchy chart, also referred to as a structure chart, is a schematic representation that breaks down a system into its sub-components. This makes it easier to understand the relationships between parts of the program and assists in identifying distinct functions that the program must perform.

To design a hierarchy chart for the given task, we usually start with a single box at the top that represents the entire program, often labeled with a title such as 'Sales Tax Calculator.' Below this, we break down into separate modules or subroutines, connected by lines indicating a relationship or flow of data. Each module might represent one of the steps provided in the exercise solution: obtaining user input, calculating sales tax, adding the sales tax to the retail price to get the total sale, and finally displaying the results to the user.

Incorporating

Exercise Improvement Advice

Effective hierarchy chart design goes beyond just depicting the components; it can also highlight areas for potential improvements. For example, the chart may reveal an unnecessary repetition of tasks or suggest a reordering of steps to improve efficiency. Simplifying complex operations into smaller, manageable chunks within the hierarchy chart facilitates better understanding and often leads to enhanced program design and development.

Sales Tax Calculation

Understanding the sales tax calculation is crucial to both the program's functionality and the user's comprehension of how the final total is derived. Sales tax is a percentage of the retail price and is calculated by multiplying the item's cost by the sales tax rate.

For the given exercise, the formula to calculate sales tax can be expressed as:
\[ \text{Sales tax} = (\text{Retail Price}) \times (\text{Sales Tax Rate}) \]
After determining the sales tax amount, the total sale amount including the tax is then calculated by adding the original retail price to the sales tax:
\[ \text{Total Sale} = \text{Retail Price} + \text{Sales Tax} \]
It's important to provide clear instructions to users for entering the correct values, such as notifying them to enter the sales tax rate in decimal form if the program expects it (e.g., enter 0.06 for a 6% tax rate).

Incorporating

Exercise Improvement Advice

The solution can be improved by validating the user input to ensure numbers are entered instead of other characters and by performing error checking or providing specific error messages if invalid input is detected. This can prevent calculation errors and improve the user experience.

Algorithm Development

Developing a solid algorithm is the bedrock of effective programming. An algorithm is a step-by-step set of operations to be performed for solving a specific problem. In essence, the step-by-step solution presented for the exercise serves as the basis for the algorithm development, which includes steps to take user input, process the input (calculate sales tax and total sale), and provide output to the user.

The flowchart developed from the exercise illustrates the algorithm visually, clarifying the sequence of operations from start to end. This visual guide aids programmers in structuring their code following the logic defined in the flowchart. Writing pseudocode is another helpful intermediary step between the flowchart and the actual coding, where each step is described in plain language resembling programming constructs.

Incorporating

Exercise Improvement Advice

While developing an algorithm, it's crucial to factor in error handling and user feedback in case of incorrect input. For our sales tax calculation program, this might include checking for negative numbers, which are not valid for price and tax rate, and prompting the user accordingly. A robust algorithm anticipates user errors and handles them gracefully, ensuring that the program is user-friendly and operates without interruption.