How to forecast (or any other function) in Google Sheets with only one cell of data?

Question

My sheet:

+---------+-----------+---------+---------+-----------+
| product | value 1   | value 2 | value 3 | value 4   |
+---------+-----------+---------+---------+-----------+
| name 1  | 700,000   | 500     | 10,000  | 2,000,000 |
+---------+-----------+---------+---------+-----------+
| name 2  | 200,000   | 800     | 20,000  | ?         |
+---------+-----------+---------+---------+-----------+
| name 3  | 100,000   | 150     | 6,000   | ?         |
+---------+-----------+---------+---------+-----------+
| name 4  | 1,000,000 | 1,000   | 25,000  | ?         |
+---------+-----------+---------+---------+-----------+
| name 5  | 2,000,000 | 1,500   | 30,000  | ?         |
+---------+-----------+---------+---------+-----------+
| name 6  | 2,500,000 | 3,000   | 65,000  | ?         |
+---------+-----------+---------+---------+-----------+
| name 7  | 300,000   | 300     | 12,000  | ?         |
+---------+-----------+---------+---------+-----------+
| name 8  | 350,000   | 200     | 9,000   | ?         |
+---------+-----------+---------+---------+-----------+
| name 9  | 900,000   | 1,200   | 28,000  | ?         |
+---------+-----------+---------+---------+-----------+
| name 10 | 150,000   | 100     | 5,000   | ?         |
+---------+-----------+---------+---------+-----------+

What I am attempting is to predict the empty columns based on the data that I do have. Maybe just one of the columns that contain data in every row or maybe I should be only focusing on one column that contains data in every row?

I have used FORECAST previously but had more data in the column that I was predicting values for which the lack of data I think is my root problem(?). Not sure if FORECAST is best for this so any recommendations for other functions are most welcome.

The last thing I can add though is that the known value in column E (value 4) is a confident number and ideally it's used in any formula that I end up with (although I am open to any other recommendations).

The formula I was using:

=FORECAST(D3,E2,$D$2:$D$11)

Answer 1

I don't think this is possible without more information. If you think about it, Value 4 can be a constant (always 2,000,000), be dependent on only one other value (say 200 times value 3), or be a complex formula (say add values 1, 2, and 3 with a constant). Each of these 3 models agree with the values for name 1, however they generate vastly different value 4 predictions.

In the case of name 2, the models would output the following for value 4: Constant: 2,000,000 Value 3: 8,000,000 Sum: 2,489,700

Each of those values could be valid without providing further constraints (either through data points or specifying the kind of model, but probably both).