Hi I'm trying to create a forecast in excel that uses dummy variables for the weeks to create seasonality as well as dummy variables for certain holidays. I created 52 weeks and then had them be 1 if the sales matched that week and 0 otherwise. I'm getting a really high p value for the weeks when I run the regression, should I still use the coefficients its giving me?
Also, it only lets me run 16 columns of X values at a time. Any ideas of how I can get around this? Below is what it looks like for me in excel, I put 1 for true and a 0 for false. I use Sales as the Y value in the regression and I tried to use all 52 weeks and the holidays as X values but it wouldn't let me. thanks
Week_ID Sales week 1 week 2 .... week 52 easter forth of July