For one of my grad school classes I am working on a projection analysis. The data includes projected year-end balances. These balances are projected every month of the fiscal year (starting in July and ending in June) to see how much approximately is the Y-T-D amount going to be. I'd like to analyze the projected balances vs. the actual Y-T-D balance.
I'd like to find a way to estimate at which month we are comfortable at saying that this is approximately what the Y-T-D amount is going to be. I thought of using confidence interval and normal distribution, but I can't figure out how to approach this.