How to perform multiple regression on quarterly seasonal data in Excel

[@thucquyen4033]

Hi Leslie, I'm doing coursework about forecasting quarterly seasonal data as well. I'm confusing about how to determine which quarter is a dummy variable. Can you please explain more on this? Thank you for your video, it's very easy to understand !

[@lesliemajor6676]

hi Thuc. I'm wondering if perhaps you are asking which quarter to exclude when performing the regression? If so - then any one you would like. The excluded variable (or quarter in this case) forms the 'base case' or the case that we are comparing to. I hope that helps?

[@hpiccus]

What if you have dates? How do you extract out the quarter numbers from a list of dates?

[@kassandramejia4451]

So, I followed all of the steps, but for some reason I keep getting a message saying "Regression - LINEST() function returns error. Please check input ranges again". For the Input Y-Range, I put the sales that were achieved for each quarter and for the Input X-Range, i put the Coded Time, Q2, Q3, Q4. I honestly don't know what I'm doing wrong.

[@Brian20Dawkins20]

You have flipped the x and y variable ranges. That is why Excel is displaying the error.

[@patriciamthethwa2375]

Thank you

[@computerman91.]

Thank you so much!

[@gerson9811]

thanks!