# How to get coefficient from logarithmic regression in Excel [closed]

Suppose that I have two columns of data, C1:C5 as inputs and D1:D5 as responses, and I set a logarithmic trendline on the resulting scatterplot. The trendline equation will be of the form $$y = a \ln(x) + b$$, where $$a$$ and $$b$$ are constants. I know the formula to extract $$b$$: INTERCEPT(C1:C5, D1:D5). What's the equivalent formula for $$a$$?

• See the help for SLOPE.
– whuber
Nov 21 at 19:05
• The only inputs for SLOPE are Known_ys and Known_xs. Nov 21 at 19:13
• That's right. The logs of the $x_i$ are the "known xs" and the $y_i$ are the "known ys." Excel computes logarithms with the LN function.
– whuber
Nov 21 at 19:17
• I'm aware of that. I still have no clue how to get that coefficient. I just need a formula to extract it. Nov 21 at 19:23
• This isn't the place for such questions. A site devoted to Excel questions would be a good place to ask it.
– whuber
Nov 21 at 19:24