What is the effect of using the PROPER function in Excel?

Using the PROPER function in Excel capitalizes the first letter of each word in a given text string while converting all other letters to lowercase. This function is particularly useful for formatting names, titles, or any text data that requires proper casing for readability and clarity.

For example, if you have the text "hello world" and apply the PROPER function, the result will be "Hello World." This functionality enhances data presentation and ensures that text strings conform to standard formatting practices for names or formal titles.

The other options do not accurately describe the purpose of the PROPER function. Capitalizing all letters refers to different functions such as UPPER, converting text to all lowercase pertains to the LOWER function, and reversing the order of characters aligns with the TEXTJOIN or other text manipulation methods that don't directly correspond to the PROPER function.