Linear Regression Formula Help

Linest Estimation.xls

Hi, hoping someone can help.

Based on the current rate of progression, which is a variable that can change on user input,
I need a formula that can estimate how many days it will take to reach the goal value.

I've tried a few different approaches, but the formulas always seem to yield inconsistent results.

Thanks for any help you can give in advance.

Figured out solution.