Statistical Analysis to predict numbers in a dataset

[Duffman]

Hi,

Suppose I have a collection of sets of numbers, lets say that each set has twenty five numbers in it (one for each day in a twenty five day period). Lets say I have 200 of these sets.

Are there any statistical methods which will help me to identify trends in the data which can predict (based on my existing sets) whether a new sets number on the 25th day day will be lower than on the first day?

For instance, suppose I am on the fifth day. Can I calculate a percentage chance that my last day will be lower than the first based on the number of observations I have so far?

Any guidance on methods that would point me in the right direction would be much appreciated. I'm using base SAS to analyze my datasets.

Thanks

Brian

[SteveDenham]

Sounds a lot like an autoregressive or moving average problem to me, with known coefficients (based on the 200 datasets).  I would recommend cross posting to the Econometrics and Forecasting forum.  Hopefully, or or one of the other folks who follow that forum regularly will have something to say on this.

Steve Denham