Final answer:
Conditional formatting in Excel is used for visual cues, like highlighting low stock in inventory sheets, imminent deadlines in project management, and failing student grades. Incorrect rule settings or data type mismatches can prevent formatting from appearing correctly.
Step-by-step explanation:
An example in which an Excel user might use conditional formatting is an inventory management sheet (A). A user could set a conditional rule to change a cell's background color to red if the stock level drops below a predefined minimum threshold. The purpose is to have a visual alert for when items need reordering. It's a way to quickly identify low stock without scanning through rows of numbers.
For a project management spreadsheet (C), conditional formatting can highlight approaching deadlines. If the current date is getting close to the deadline date, the cell color could change, drawing attention to the tasks that need urgent attention.
Lastly, in a student grade tracker (D), conditional formatting can be used to highlight failing grades. If a grade falls below a certain passing threshold, it can be highlighted to quickly notify that intervention might be needed to help the student improve.
Conditional formatting might not work as expected if the rules are not set correctly. This could be because the conditions for formatting were not accurately specified or there's a data type mismatch in the cells.