Final answer:
To draw a horizontal line of a given length on the screen, you need to use a scale. Modify the program to add a length parameter and change the loop to display numbers from 1 to the given length. Run the modified program to verify the changes.
Step-by-step explanation:
To draw a horizontal line of a given length, you need to use a scale. The scale is a ratio that represents the relationship between the actual length and the length on the display. In this case, the unit scale is used, where 500 feet is represented by 5 inches. So, for a line 8 inches long on the display, the actual length would be 800 feet.
To modify the program, you need to add a length parameter to the module and change the loop to display numbers from 1 to the given length. For example, if you pass 8 as the length, the program should display numbers 1 to 8 on the screen.
By running the modified program and verifying that it displays the numbers from 1 to the given length, you can confirm that the changes have been successfully implemented.