Coding Assignment: Annual Sales Calculator

Objective:

collecting and processing the data, the program will print the average monthly sales and total annual sales.

Requirements:

User Input:

Prompt the user to enter the number of years they want to calculate sales for.

For each year, prompt the user to enter the sales amount for each month $(12$ months per year$).$

Input Validation:

Ensure the number of years entered is at least $1.$ If not, display an error message and prompt the user to enter a valid number.

Ensure that all sales amounts are non$-$negative. If a negative value is entered, display an error message and prompt the user to re$-$enter the value.

Calculations:

Calculate the total sales for each year.

Calculate the average monthly sales over the entire period.

Methods:

Value$-$Returning Method $1$: Create a method that takes the total sales and the number of months as parameters, and returns the average sales.

Value$-$Returning Method $2$: Create a method that validates user input $($for years and sales amounts$)$ and returns the validated value.

Non$-$Value$-$Returning Method: Create a method that prints the total sales and average sales in a formatted manner.

Output:

Format all dollar amounts to two decimal places.

Print the total sales for the entire period.

Print the average monthly sales.