Calculating values for empty cells.

[Ryan Taylor]

Hello.

I have a very simple problem that I cannot find the answer to. I have data
in two columns, some of the data in one of the columns is missing and I want
to automatically extrapolate what the data should be based on the trend. How
can I get Excel to fill in empty values without overwriting the known
values. Below is a sample of my data.

1500
1600
1700
1800
4000 1887
5700 1900
5500 1910
7300 1912
8100 1920
8800 1926
10100 1930
11900 1936
12200 1938

 

[J.E. McGimpsey]

Not sure what you mean by "automatically", here, but you can
extrapolate the values using this array-entered formula
(CTRL-SHIFT-ENTER or CMD-RETURN):

Assume data in A1:B13. Select B1:B4 and array-enter

=TREND(B5:B13,A5:A13,A1:A4)

If the series is an exponential growth series, use GROWTH() instead.