Google Sheets: How to have the same values in column 4 whenever there are duplicate values in column 1?

Question

The image explains what I would like to achieve probably the best:

The table I would like to create, at the moment I have only first three columns:

I would like the "New Volume" to have the same values whenever the keyword repeats. At the moment I have the three first columns but cannot figure out with what formula I can create the "New Volume" column.

I would appreciate the help.

Answer 1

This is a vlookup job.

=vlookup(D3;$D$3:$E$8;2;false)

It searches D column for identifier (also in column D) and returns value from second column. When vlookup is set as false, will always return first found value.

To avoid copying down the formula, you can nest it with arrayformula:

=ArrayFormula(ifna(vlookup(D3:D;$D$3:$E;2;false)))

My solution is here: https://docs.google.com/spreadsheets/d/1RpSsb6DmUs6lcPmZ1R6uPW-a3iWs9XEnSpc3b3XiihI/edit?usp=sharing