The article will show you how to calculate **Critical Z Score** in Excel. Itâ€™s an important parameter in the field of statistics. It tells us whether a **hypothesis test** is under the **rejection region **or not. With that help, we can find out the significance of any value in the data. A **critical value** can also give us the probability within the distribution region.

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## What Is Critical Z Score?

The **Critical Z Score **is a value that refers to the area under the **Standard Normal **model. This is a vertical line that separates the **distribution region **into two sections. This value also emphasizes how the **Standard Deviation **varies from the **Mean**. We often use the **Critical Z Score **value when the **sampling distribution **is normal or approximately equal to normal. It also has a great significance while calculating the probability for an unknown **Standard Deviation**.

## 3 Examples to Calculate Critical Z Score in Excel

In the dataset, we will calculate for **2 **different **significance levels** (**Î±**).

**1.Â ****Calculating ****Critical Z Score for Right-Tailed Test**

A **Right-Tailed Test** is the test to determine ifÂ your hypothesis experiment is less than a **significance level**. In other words, it is the distribution region to the left side of that **level**. The basic way to calculate **Critical Z** Score in Excel is to use **the NORM.S.INV function**. This a dedicated Excel function to calculate Critical Z Score. We will be using this function to calculate the **Right-Tailed Critical Z Score**. Letâ€™s go through the discussion below.

**Steps:**

- First, make a column to store the
**Critical Z Score**values and type the following formula in cell**C5**.

`=NORM.S.INV(1-B5)`

The formula here returns the **Right-Tailed Critical value **for a **level of significance **of **0.1 **or **10%**.

- After that, hit the
**ENTER**button to see the**Right-Tailed Critical Z Score**.

- Thereafter, use the
**Fill Handle**to**AutoFill**the lower cell.

Finally, you will get the value of the **Right-Tailed Critical Z Score **for both **0.05 **and **0.1**. Note that, these values are positive because they are right to the distribution region.

Thus you can calculate the **Right-Tailed Critical Z Score **in Excel.

**2. ****Determining ****Critical Z Score for Left-Tailed Test**

A **Left-Tailed Test** is a test to determine if your hypothesis experiment is greater than a **significance level**. In other words, it is the distribution region to the right side of that **level**. The basic way to calculate Critical Z Score in Excel is to use **the NORM.S.INV function**. This is a dedicated Excel function to calculate **Critical Z Score**. We will be using this function to calculate the **Left-Tailed Critical Z Score**. Letâ€™s go through the discussion below.

**Steps:**

- First, make a column to store the
**Critical Z Score**values and type the following formula in cell**D5**.

`=NORM.S.INV(B5)`

The formula here returns the **Left-Tailed Critical value **for a **level of significance **of **0.1 **or **10%**.

- After that, hit the
**ENTER**button to see the**Left-Tailed Critical Z Score**.

- Thereafter, use the
**Fill Handle**to**AutoFill**the lower cell.

Finally, you will get the value of the **Left-Tailed Critical Z Score **for both **0.05 **and **0.1**. Note that, these values are negative because they are left to the distribution region.

Thus you can calculate the **Left-Tailed Critical Z Score **in Excel.

**3. Calculating Critical Z Score for Two-Tailed Test**

A **Two-Tailed Test** is a process where the critical area of a distribution has a **two directional** region and checks if a value is within the normal distribution region. This test is widely used in null-hypothesis experiments for statistical significance. If the value falls into any of the **critical regions**. The basic way to calculate **Critical Z Score** in Excel is to use the **NORM.S.INV** function. This a dedicated Excel function to calculate **Critical Z Score**. We will be using this function to calculate the** Two-Tailed Critical Z Score**. Letâ€™s go through the discussion below.

**Steps:**

- First, make a column to store the
**Critical Z Score**values and type the following formula in cell**D5**.

`=NORM.S.INV($B$5/2)`

The formula here returns one of the **Two-Tailed Critical values **for a **level of significance **of **0.1 **or **10%**.

- Hit the
**ENTER**button and you will see the**left-sided**value of this**Two-Tailed test**.

- To get the other value of the
**Two-Tailed Test**, type the formula below in**C6**and press**ENTER**.

`=NORM.S.INV((1-$B$5/2))`

This will return the other value of the **Two-Tailed Test**.

- Similarly, use the following formula to calculate
**left sided**value of**Two-Tailed Test**for a**significance level**of**0.05**or**5%**and hit the**ENTER**button.

`=NORM.S.INV($B$7/2)`

- Thereafter, use this formula to calculate
**right sided**value of**Two-Tailed Test**for a**significance level**of**05**or**5%**and hit the**ENTER**button.

Thus you can get the values of the **Two-Tailed Critical Z Score **for both **0.05 **and **0.1**. Note that, these values have both** positive** and **negative signs** because they are within theÂ distribution region and this region has **positive** and **negative** values in its right and left side respectively.

Thus you can calculate the **Two-Tailed Critical Z Score**.

## Practice Section

Here, Iâ€™m giving you the dataset of this article so that you can practice these methods on your own.

## Conclusion

The fact to the matter is, this article provides you all the possible examples of how to calculate **Critical Z Score **in Excel in different conditions. If you have any better methods or questions or feedback regarding this article, please share them in the comment box. This will help me enrich my upcoming articles. For more queries, kindly visit our website **ExcelDemy.com**