In this tutorial we will learn how to perform Z Test in Excel. When we want to compare two means when variance are known, then we use Z Test. Z Test is the test of null hypothesis, which states the mean of two population are equal.

**H _{0}: μ_{1} – μ_{2} = 0**

**H**

_{1}: μ_{1}– μ_{2}≠ 0Alternate hypothesis H1 states that the two population means are not equal.

**Note: **Z test is performed when the variance of the two population are known

**Data:**

We will be using the scores of students across two different subjects to depict example on Z test in Excel, Which is shown below.

**Step 1: **calculate population variance of variable 1 and variable 2 with **VAR.P** formula as shown below

**Step 2:** On the top right corner of the data tab click data analysis.

**Note:** if you can’t able to find the Data Analysis button? Click here to load the **Analysis ToolPak** add-in.

**Step 3:** Select Z – Test: Two Sample for Means and click ok

**Step 4:** Click in the Input Range boxes and select the Variable 1 Range **A2:A10** and Variable 2 Range **B2:B10. **Mention the** variable 1 variance **and** variable 2 variance **that we have calculated and also mention the output range as shown below and click ok

So the result will be

If **z **< **– z Critical two-tail** or **z Stat** > **z Critical two-tail**, we reject the null hypothesis. In our case 0.213 > -1.959 and 0.213 < 1.959, so we cannot reject null hypothesis. So both the means do not differ significantly.