Fill in Missing Data Based on previous column [cell] value

[#1]

I apologize for this redundant question about column fill but for the life of me i can't find any of the previous topics.

I have a data table that is filled out in an incomplete manner. I need to fill the missing cells below each value with its predecessor. I know it is a Column Formula script that uses the Lag() and Row() but can't find the correct syntax.

[#2 · Accepted solution]

@jules has the perfect answer here... if a picture is worth 1000 words, a .gif is worth 1e6.

https://community.jmp.com/t5/Discussions/Fill-consecutive-rows/m-p/366760