Hello, I tried the search function on the LOGEST function and there were some interesting threads but none that addressed my topic.

I have inherited a spreadsheet that has a LOGEST function in it. However, it has something as simple as =LOGEST(B2:B8)-1 in it for a calculation.

Say the values are

100
107
115
111
114
121
118

if I use the LOGEST function to that data set and subtract 1 I get an average change of 2.6%. I think.

How can I reproduce this result using the LOGEST formula, but using my inputs as an array? LOGEST assumes the formula y=b*m^x, but what does the 2.6% have to do with the b or m parameters?

Further, and perhaps most important to me, what are the "known y's" when you only have something like LOGEST(B2:B8), with no "known y's" in it? Don't you need the "known y's" ?

Seasons greetings,

Gareth Keenan