Question: how to use excel to calculate z value?
Answer: Excel Z Score (Table of Contents)
Z = (x-µ) / σ
Mean (or Average) calculation:
Step 1 – Go to the Formulas tab. ... 
Step 2 – Now click on Statistical functions category from the drop-down list. ... 
Step 3 – It will open a Function Arguments dialog box. ... 
Standard Deviation calculation:
Step 1 – Go to the Formulas tab.