Quote Originally Posted by coeeze
Is regression preferred over multiplying by a rate or moving average to generate a forecast? In my case the data is seasonal.
You are correct that this more math/stats than Excel. Linear regression like this would only be preferred if you expect the data to actually follow a simple linear trend. A simple linear trend cannot account for seasonality, so I would not expect linear regression to be preferred in this case.

Quote Originally Posted by coeeze
do you know if there are any functions in Excel I could use to find m and b?
List of available statistical functions: https://support.office.com/en-us/art...__toc309306716 There is the =SLOPE() and =INTERCEPT() functions. I generally use the =LINEST() function. The =AVERAGE() function could be formulated to create a moving average, if you decide that is a better approach. Other statistical methods can be used as well.