How to Create Skewed Bell Curve in Excel

[@antonynganga7868]

Great excel learning content,just a question for you Sir,at the bin section,the formula indicates minus 3 multiplied by the mean,where is minus 3 coming from?Or what is minus 3 in the formula?

[@exceldemy2006]

Dear @antonynganga7868, Thank you for your query. The bell curve shown in the example is positively skewed so most of the data points are located to the left of the mean value. Therefore for the minimum bin value, we’ve considered 3 standard deviations left from the mean, that is, mean - 3*standard deviation. Another important thing to remember is that the Empirical rule for normal distribution states that 99.7% of the observations lie within 3 standard deviations from the mean. Since this covers almost the entire dataset, we’ve chosen this limit as our minimum bin value. Hope you find this helpful. Regards, ExcelDemy Team!

[@Karta_mysh]

Thanks, that's what I was looking for.

[@monaswanson3021]

When you make the positively skewed graph, you select the second row through the "more" row under bin frequency. When you make the negatively skewed graph, you select the first row through the last row of numbers and you do not include the "more" row. Why is that?

[@exceldemy2006]

Dear @monaswanson3021, Thank you for your feedback. You asked an interesting question. When making the positively skewed bell curve we chose the data from the second row since there are no data points within the first bin range i.e. its frequency is zero. Likewise, in the case of the negatively skewed bell curve, the overflow bin (More rows) has no data points. Therefore, we chose to ignore these bin ranges when creating the positive and negative bell curves. Make sure to stay connected with Exceldemy! 🎉❤. Have a good day. Regards, Exceldemy

[@nuralianatasha2630]

helo can you help me on how to create kurtosis graph in excel too?

[@exceldemy2006]

Dear @nuralianatasha2630, Thanks for your feedback. Regarding your question on creating a kurtosis graph in Excel. Kurtosis is a statistical measure that describes the tail heaviness of a distribution compared to normal distribution. A positive kurtosis indicates heavier tails than a normal distribution, while negative kurtosis implies lighter tails. Therefore, there are no separate kurtosis graphs, rather we calculate the kurtosis value of a distribution. You can use Excel’s KURT function to easily the kurtosis value. Just follow the steps in the article below. Article link: www.exceldemy.com/how-to-calculate-kurtosis-in-excel/ Make sure to stay connected with ExcelDemy!🎉❤. Have a good day. Regards, ExcelDemy

[@nanjaare]

what if there are multiple modes?

[@exceldemy2006]

Dear, Thanks for your question! You are working with data that has multiple modes. Multiple modes in the dataset can affect the shape of the bull curve. So, you can apply other visualization methods, like KDE and Ridge plots, in this case, to better present its distribution.

[@santoshkiran5858]

Awesome 👍

[@exceldemy2006]

Thank you! Stay connected with Exceldemy for more helpful content! 🎉❤ Regards, Exceldemy Team!

[@AzhanBinHassan]

Why did we take 6 BIN values?

[@exceldemy2006]

Hello @AzhanBinHassan, The 6 BIN values are selected to divide the data into intervals that help create a clearer distribution for the skewed bell curve. These bins allow us to group data points and plot frequencies across the curve, showing the skewness. The number of BINs can vary depending on the data size and distribution. More or fewer bins can adjust the smoothness and detail of the curve. Regards ExcelDemy

[@annissaqzulkifle1446]

Why for first bin need to -3

[@exceldemy2006]

Hello @annissaqzulkifle1446, The -3 in the first bin is typically used to establish the starting point for the histogram, ensuring it captures values that fall below the mean in a skewed distribution. Using -3 is common because it captures a significant portion of the distribution, extending three standard deviations below the mean, which encompasses about 99.7% of the data in a normal distribution. This helps account for outliers and ensures the histogram accurately represents the skewness of the data. Regards ExcelDemy

[@mdsadiq2786]

PlZ share this file

[@exceldemy2006]

Hello @mdsadiq2786, Thanks for watching our video. Here is the Excel file: www.exceldemy.com/wp-content/uploads/2022/06/Create-a-Skewed-Bell-Curve-1.xlsx The Excel file and article link are also given in the video description. Regards ExcelDemy