How to sum up items until a minimum threshold is met?

Hi all,

I'm wondering if anyone can help. I'm trying to sum up the values in a column until a certain value is met, however, I need it based on the lines of "until at least the threshold is met".

Within my data, I have a list of items (Column A), each with a sales value (column B) and a representation of what % each item accounts for (column C). I need to display in column D which of these items sit within the top 70%, however, the first 5 items make up 69% and the next item take the total up to 78% - meaning the 6th item appears as a "No", when I actually need it to say yes. I've shown the formula that I've currently been trying to use and having issues with.

I'm not sure if this makes sense, but hopefully my example gives a bit more context. I just need to sum all the items in column C until at least 70% is reached and those items to display a "Y" in column D.

Is this possible?

Thanks very much !