I have a pretty basic question, but am pretty far removed from stats and modeling.
I have historical data (daily, weekly, monthly, however I want to slice) for a few years and I want to predict the probability of hitting an end of month target throughout the month. The data follows very similar trends, if you overlay 1 week over any other week in the year, it's practically the same line.
I thought of a few ways to do this, but don't know if they're correct. 1) Using a poisson, I can plug in the historical average values from any day X to end of the month. I also have a target from day X to end of month, and with the historicals, I will know how many successful times that amount has been reached. So using P = (e^-u)(x^u)/x!, u = average historicals, x = # times those historicals exceed the remaining target. 2) since every day has a very similar outcome, I could count how many Mondays, Tuesdays.... are left in the month, calculate an interval in which I'm 99% sure each day will come in between X and Y. Add the lower and upper limits on each day and by the end of the month can I say I'm 99% sure value will be between X1+X2+... and Y1+Y2+...
thoughts and help very much appreciated.