Excel Z Score

Excel Z Score (Table of Contents)

• Z Score in Excel
• How to Calculate Z Score in Excel?

Z Score in Excel

Z Score is used for statistical measurement. It is also known as a standard score. The value of the Z score is the measurement of the number of standard deviations a specific number is above or below a mean.

The below formula is used to calculate the Z score:

Z = (x-µ) / σ

Where the supplied arguments are as below:

• Z = It denotes the Z score value.
• X = The value to be standardized.
• µ = Mean of the given data set values.
• σ = Standard deviation of the given data set values.

How to Calculate Z Score in Excel?

Calculation of Z Score in excel is very simple and easy. Let’s understand how to calculate the Z score in excel with some examples.

Excel Z Score – Example #1

We have given marks of some students as below:

Now for calculating Z Score, we need to find out the Mean and standard deviation of the given dataset in excel.

Mean (or Average) calculation:

For finding the average, follow the below steps:

Step 1 – Go to the Formulas tab. Click on More Functions options under the Functions Library section.

Step 2 – Now click on the Statistical functions category from the drop-down list. It will again open a list of functions. Click on the AVERAGE function as shown below.

Step 3 – It will open a Function Arguments dialog box. Enter the Range from Cells B4:B13 under field Number1 and click on OK.

• It will give you the Average or Mean value.

Standard Deviation calculation:

For finding the standard deviation, follow the below steps:

Step 1 – Go to the Formulas tab. Click on More Functions under the Function Library section.

Step 2 – Click on the Statistical Function category from the drop-down list. It will open a list of functions. Click on STDEVPA from the list as shown in the below screenshot.

Step 3 – It will open a Function Arguments dialog box. Enter the cells range from B4:B13 under field Value1 and click on OK.

• It will give you the standard deviation value.

Now we have to calculate the Z score values in excel. For this, follow the below screenshots:

• Go to the FORMULAS tab. Click on the More Functions option under the Function Library section.

• Then a drop-down list of functions will open. Click on Statistical functions from the list. It will open a list of functions. Click on STANDARDIZE function from the list as per the below screenshot.

• Then it will open a Function Arguments dialog box. Enter the Cell value B4 under field X.

• Enter the Mean value in the second field, Mean, which is mentioned under Cell B15.

• Enter the Standard Deviation value in the third field, Standard_dev, which is mentioned under Cell B16. Click on OK.

• The result will be as given below.

• Drag this formula for the rest values, and it will pop up the Z score values in excel as shown below:

Explanation

• If we analyze the data, the highest Z score value is 2.082778, which is the Z score value of Nick Brown, who has achieved the highest score in the exam.
• The smallest Z score value is -0.98521, which is the lowest Z score value of Adrian Steve, who has achieved the lowest score in the exam.
• There can be positive and negative values in Z scores.
• Students who have achieved scores more than the mean value get positive Z scores.
• Students who have achieved scores less than the mean value get negative Z scores.
• If the Z score is zero, that means the student’s score is the same as the mean value.

Excel Z Score – Example #2

We have given the below data values.

To calculate the Z score or standard score, we need to determine the first mean and standard deviation in excel.

• Let’s apply the AVERAGE formula for calculating the mean of the given dataset.

• It will give you the Average or Mean value.

For calculating standard deviation, let’s apply the STDEVPA function for the given data values as per the below screenshot.

• It will give you the standard deviation value.

• Now we will calculate Z score values in excel. For this, apply the STANDARDIZE function for the given data values as per the below screenshot.

• The result will be as given below.

• Drag this formula for the rest values. The Final result is given below:

As we can see, the positive value of Z scores are higher than the mean value, and the negative value of Z scores are lower than the mean value.

Things to Remember

• The Z score tells us a number of standard deviations that are away from the mean of the distribution or dataset.
• The data values which are higher than the mean Z score will be a positive value.
• Data values which are below the mean Z score will be a negative value.
• The z score value is probably used for statistical analysis.

Recommended Articles

This has been a guide to Z Score in Excel. Here we discuss how to calculate Z Score in excel along with practical examples and a downloadable excel template. You can also go through our other suggested articles –

1. Excel AVERAGE Function
2. Standard Deviation in Excel
3. Z TEST in Excel
4. Excel Frequency Distribution