in this article, we’ll demonstrate 3 different examples of finding the Z Critical Value in Excel. The Z Critical Value plays a significant role in a Hypothesis Test. A Hypothesis Test generates a Test Statistic as the result, but to determine if this result is statistically significant or not, a comparison should be made between the Test Statistic and the Z Critical Value.

## Introduction to the NORM.S.INV Function

**The NORM.S.INV function** in Excel determines the inverse of the standard normal cumulative distribution. The Mean is Zero and the Standard Deviation is 1 in the cumulative distribution.

**Syntax**

**=NORM.S.INV(probability)**

**Arguments**

** probability:** A probability corresponding to the standard normal cumulative distribution.

## How to Find the Z Critical Value in Excel: 3 Suitable Examples

For hypothesis test results to be considered statistically significant, the absolute value of the test statistic needs to be greater than the **Z critical value**. To illustrate, we’ll use the below dataset where the **Significance Level** (**α**) is **0.05** and compute the **Z critical value** for 3 different test types.

### Example 1 – Calculate the Z Critical Value in a Left-Tailed Test

Let’s find the critical value by applying the **Significance Level** (**α**) as a probability in the argument of the **NORM.S.INV** function.

**Steps:**

- Select cell
**C7**. - Enter the following formula:

`=NORM.S.INV(C4)`

- Press
**Enter**to return the value.

The desired result is returned.

### Example 2 – Find the Z Critical Value in a Right-Tailed Test

As in the case of a left-tailed test, one critical value is also returned as output of a **Right-Tailed** test. In a right-tailed test case, we need to subtract the **Significance Level **from **1**, so we’ll modify the **Significance Level** (**α**) to insert it in the argument of the **NORM.S.INV** function.

**STEPS:**

- Select cell
**C8**. - Insert the below formula:

`=NORM.S.INV(1-C4)`

- Return the result by pressing
**Enter**.

The **Z critical value** for the right-tailed test is returned.

**Read More: **How to Find T Critical Value in Excel

### Example 3 – Determine the Z Critical Value for a Two-Tailed Test

A** Two-Tailed test **returns 2 critical values as output. We’ll input the **Significance Level** (**α**) as a probability in the argument of the **NORM.S.INV** function, but we’ll have to edit it first. As it’s two-tailed, we’ll divide the **Significance Level **by **2** to get one critical value. Then, to find the second critical value, we’ll subtract the division output from 1.

**STEPS:**

- Click on cell
**C9**. - Enter the formula below:

`=NORM.S.INV(C4/2)`

- Press
**Enter**to return the result.

- To find the second critical value, select cell
**C10**. - Enter the formula below:

`=NORM.S.INV(1-C4/2)`

** **

- Press
**Enter**.

The two critical values for the two-tailed test are returned.

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