Final answer:
The student's question seeks the creation of a program to track sales for three families at a garage sale. The program, Garage Sale GUI, will keep running totals and display them once the user signals the end by entering 'Z' or 'z'.
Step-by-step explanation:
The question is about creating a console-based application named Garage Sale GUI for tracking the sales of three families during a garage sale. The program should prompt the user for the initial of the family ('A', 'B', or 'C'), and accept both uppercase and lowercase inputs. While the user does not enter 'Z' or 'z', the program will ask for the amount of a sale and add it to the respective family's total. When 'Z' or 'z' is entered, the application should display the total sales for each family and a grand total of sales made at the garage sale.