Use `=STDEV.S(range)` for a sample standard deviation
Use `=STDEV.P(range)` for a population standard deviation
Select an empty cell
Type the formula with your data range
Press Enter
Replace `range` with the actual cell range, such as `A1:A10`
Example: `=STDEV.S(A1:A10)`
Example: `=STDEV.P(A1:A10)`