Use `=(A1-AVERAGE($A$1:$A$10))/STDEV.S($A$1:$A$10)`
Replace `A1` with the cell containing the value
Replace `$A$1:$A$10` with the data range
Use `STDEV.P` instead of `STDEV.S` for an entire population
Use `=STANDARDIZE(A1,AVERAGE($A$1:$A$10),STDEV.S($A$1:$A$10))`
Press Enter to get the z-score
Copy the formula down for other values