Hi I have a problem with my project. I have 1000 data and i used it as training data to forecast with Timeseries. My Lecture suggested me to use value for determine cut off or not, rather than use graph. Here's my ACF Value. [![enter image description here][1]][1] Is there any syntax in R to know the upper limit and lower limit of ACF? Thankyou in Advanced. If you don't understand, let me know. :D [1]: https://i.sstatic.net/RJiYb.png