The article will show you how to transform data to the normal distribution in Excel. In statistics, it’s important to imply the normal distribution concept to understand the position of a single or multiple data in the dataset. Calculating manually the normal distribution values of data is time consuming and also a tiresome process. Fortunately, we have a function in Excel which can solve our problem in an instant. The name of this function is NORM.DIST. Let’s go through the rest of the article for a better understanding.
What Is Normal Distribution?
Normal distribution is also known as Gaussian distribution. It is the probability distribution of a sample space. The distribution of these data is symmetric to the mean. It is also a measurement of how much data close to the mean appears more than data far from the mean. It’s important to know that the mean is zero and the Standard Deviation is 1 in a normal distribution. In practical life, normal distribution helps us to understand the significance of data in a group of data. The equation to find normal distribution in a set of data is given below.
Where,
σ = Standard Deviation
x = Sample Data
μ = Average/Mean
2 Ways to Transform Data to Normal Distribution in Excel
In the dataset, we have information about some students’ performance by score in an examination. We will determine who did an outstanding performance in that exam by transforming their score into normal distribution using Excel.
1. Using Excel Function to Transform Data to Normal Distribution
The best way to transform your data to normal distribution will be to use Excel NORM.DIST Function. It will automatically calculate the normal distribution data by using the aforementioned formula. Let’s go through the process below.
Steps:
- First, make a column to store the normal distribution values and also select two cells to store your Mean and Standard Deviation.
- Type the following formula to calculate the Mean and press ENTER. You will see the Mean of the Marks of these students.
=AVERAGE(C5:C11)
Here, the AVERAGE Function returns the Mean value of the Marks of the students.
- After that, use the following formula to calculate the Standard Deviation.
=STDEV.P(C5:C11)
The STDEV.P Function returns the Standard Deviation of this data.
- Next, type the following formula in cell D5.
=NORM.DIST(C5,$C$13,$C$14,FALSE)
- Later, hit the ENTER button and you will see the normal distribution value of the marks in cell C5.
- After that, use the Fill Handle to AutoFill the lower cells.
Thus you can transform all the data of your dataset to the normal distribution in Excel.
- If you want to show your data in a normal distribution graph, please select the range C4:D11.
- After that, go to Insert >> Scatter with Smooth Lines
Thereafter, you will see the data in a normal distribution graph.
Keep in mind that, approximately 68% of your data are between Average ± Standard Deviation range, 95% of your data are between Average ± 2*Standard Deviation and 99.7% of your data will fall between Average ± 3*Standard Deviation range. That means, 68% of the students have a score between 74.57 ± 10.66 or 63.91 to 85.23. Similarly, you can determine the other ranges for 95% and 99.7%.
2. Applying Mathematical Formula to Transform Data to Normal Distribution
If you are good at statistics and not interested in using the built-in NORM.DIST Function, you can use the mathematical formula of the Normal Distribution. Let’s go through the process below.
Steps:
- First, make a column to store the normal distribution values and also select two cells to store your Mean and Standard Deviation.
- Calculate the Mean and Standard Deviation following the process of Section 1.
- Next, type the following formula in cell D5.
=EXP(-0.5*((C5-$C$13)/$C$14)^2)/($C$14*SQRT(2*PI()))
Here, the formula uses EXP and SQRT Functions to generate the mathematical formula of normal distribution transformation. It will return the normal distribution value of your data.
- Later, hit the ENTER button and you will see the normal distribution value of the marks in cell C5.
- After that, use the Fill Handle to AutoFill the lower cells.
Thus you can transform all the data of your dataset to normal distribution using the mathematical formula.
- If you want to show your data in a normal distribution graph, please follow this link of Section 1.
Practice Section
Here, I’m giving you the dataset of this article so that you can practice these methods on your own.
Conclusion
Suffice to say, this article will help you to understand the basic methods on how to transform data to normal distribution in Excel. 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.