How do you create an array formula in a spreadsheet?

To create an array formula in a spreadsheet, the process typically involves entering the formula and then confirming it by pressing Ctrl + Shift + Enter. This combination of keys signals to the spreadsheet that the formula should treat the data as an array, allowing for operations that can return multiple values or operate on multiple cells in a single formula.

Array formulas are particularly useful for performing calculations on a range of cells or generating a number of outputs from a single input. For instance, they can allow users to sum or average multiple columns or rows based on specific criteria without the need for additional helper cells.

The other options do not correctly describe the process for creating an array formula. For example, pressing just Shift + Enter does not activate array functionality in spreadsheets. Similarly, simply typing the formula in a header cell or entering it without any special key combination does not create an array formula and would yield a standard formula instead.