Quadratic Regression Analysis in Excel
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- Опубликовано: 5 сен 2024
- This video providses step-by-step instructions on how to do a quadratic (2nd-order) regression analysis (least-squares curve fit) using Microsoft Excel, and then how to plot the results.
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Dr. John M. Cimbala is Professor of Mechanical Engineering at Penn State. He is an educator, textbook author, Christian author, husband, father, and grandfather. He also created and maintains a website for helping people grow in their faith called Christian Faith Grower at www.christianf...
WOW! I searched for 9 hours and yours is the only video who solved my problem in two minutes. I love you king
Thank you for your comment. Please tell your students about my videos - they can be used as supplements for the book and course. Also, please tell your friends and colleagues about my RUclips channel where there are more than 400 free videos about the Bible, fluid mechanics, science, math, statistics, air pollution, and other topics. I would greatly appreciate it.
Outstanding. Quick and clear and easy. Wish all videos were like this. Thanks
Thank you for your kind comment. Please tell your friends and colleagues about my RUclips channel where there are hundreds of free videos about fluid mechanics, science, math, statistics, the Bible, air pollution, and other topics. i would appreciate it.
Wow. Your explanation is amazing! Its short, simple and full of information. You just saved me, sir.
OMG THANK YOU!!! I was going. Crazy!!
Thank you for your comment. Please tell your students about my videos - they can be used as supplements for the book and course. Also, please tell your friends and colleagues about my RUclips channel where there are more than 400 free videos about the Bible, fluid mechanics, science, math, statistics, air pollution, and other topics. I would greatly appreciate it.
@@johncimbala already done!
Awesome Video!
Thank you for your kind comment. Please tell your friends and colleagues about my RUclips channel where there are hundreds of free videos about the Bible, fluid mechanics, science, math, statistics, air pollution, and other topics. I would greatly appreciate it.
Its 2022 and this video helped me a lot. Thank you John!
Thank you for the feedback!
Thank you for explaining how the Multiple R data fits into what what is actually going on in a way I easily understood!
seriously. THANK YOU!
Thank you so much for this tutorial! It was concise and straight-forward to understand.
Thank you Sir, very clear explanation, a dummy like me can understand it well. I very much appreciate it.
Thank you! This is the best video tutorial for this, short and simple
Glad it was helpful.
You sir are a life-saver!
What a clear and concise explanation!
Thank you.
Got an 'A' on my assignment and I just graduated, thank you for your contribution in that!
Very clear explanation. Thanks!
Thanks a lot, helped me very much!
Thanks!! Done on Excel 2016
Great help. Thanks.
Great! Really! Thank you for taking your time to make such a video, it really helped me! Thank you once again very much!
You are most welcome.
Very precise one...
Nice
Thank you, please to use the quadratic fit to solve for unknowns what would be the equation for the quadratic curve?
Thanks sir. it is useful :)
Fantastic
Thanks a lot Sir!
Glad it was helpful.
thank you!! is it possible to find the limit of detection (LOD) from second-order polynomial fitting
Not sure. What I show in the video is simply a curve fit - what is the best curve through the data. I suppose if there were data that could be curve fit this way to help determine LOD, but only if the data fit well with a polynomial (which, by the way can be of any order, not just second order).
Thank you for your comment. Please tell your friends and colleagues about my RUclips channel where there are hundreds of free videos about the Bible, fluid mechanics, science, math, statistics, air pollution, and other topics. I would greatly appreciate it.
Awesome
2:42 how did you add 2 "$" suddenly???
Hit the Function F4 button after you click on a cell.
@@johncimbala So useful!
@@2339091q Thank you for your comment. Please tell your friends and colleagues about my RUclips channel where there are more than 400 free videos about the Bible, fluid mechanics, science, math, statistics, air pollution, and other topics. I would greatly appreciate it.
@@johncimbala actually I think my best support is to like your vids and subscribe. good luck John!
@@2339091q I have a playlist with Excel tutorials if that is what will help you.
Can I have didfferent S.E Standard error for each y's???
I don't understand your question
Hey John, great explanation! I do have a question tho, is it still possible to interpolate in the quadratic regression curve?
For example if I have a sample. The ‘x-value’ is in my case the concentration and the ‘y-value’ is the peak intensity. To make the quadratic regression curve I'm correcting the peak intensities, by using the known concentrations of the samples.
When I measure a new sample, I obtain the ‘normal’ peak intensity. I need to correct this using the concentration, but since the concentration is unknown, I’m not able to correct the peak intensity. Normally I would determinate the concentration by interpolating the found peak intensity in the curve, but because I need to correct the peak intensity, using the concentration, this is not possible. Am I still able to determinate the unknown concentration? Can I correct the peak intensity using the theoretical concentration and then interpolate the corrected peak intensity in the curve to obtain the concentration? I would really appreciate it if you could give me some advice 😊.
Not exactly sure what you mean. You may need to iterate to converge on the best solution
if i wanted a 3rd or more degree polynomial analysis would i need to make an X1, X2(^2) and X3(^3)... column? or just an X1 and X2 column with the equation in the 2nd column being cubed?
Need third column.
May i know what is meant by Standard Error at each intercept and slope variables results? I kinda confused to write about the error of the analysis.
it is kind of like a standard deviation for regression analysis and you are correct - it can be used to generate the confidence intervals.
Do you offer any online tutoring ?
No, I am not getting into that.
Alrite now i blieve this is a true polinomical regression.
Won't the model suffer from 100percent correlated independent variables
I don't think so. It is treating each independent variable separately.
John Cimbala thanks for the reply. But I am still confused, does it not go against the assumptions of linear regression that the X variables should be totally independent/uncorrelated.
I see your point. However, x and x^2 and x^3... are NOT correlated linearly. Maybe that's why it treats them like independent variables. NOTE: I have repeated the analysis shown in my video but with a PERFECT quadratic equation (no scatter), and the results come out with perfect coefficients, exactly the ones from which I constructed the equation. Try it, you will see. It works.
John Cimbala For the correlation, if we check it in excel itself it would come as high as 98%. We do obtain an equation and it does fit the curve. And that's what surprises me. For a models like this can we trust it's Rsquare and variable coefficients. I believe in statistical packages like SAS there is a separate proc called nlin to work with non linear regression. I am not sure what faults does this excel model contain and how do we find them.
I don't know the inner workings of Excel either, but if you want to see my Excel file with PERFECT correlation, I can send it to you. I just need an email address. Mine is on my website - google my name.