how to build the formula??

[solty89]

qwerrtqrerrew

[canapone]

Hi

=LOG(400,1.15)

Regards

[ben_hensel]

sombody doesn't remember logarithms from school!!!

b^y = x

logb(x) = y

change of base:
y= ln(x) / ln(b)

Specifics for excel here:
= ln(400)/ln(1.15)


EDIT:
...or you could use the LOG formula, that works too, probably even better, actually. (I often forget it exists because I habitually put things in ln(x)/ln(base) forms from my school days.)

[solty89]

Hi

=LOG(400,1.15)

Regards

thanks canapone

[canapone]

Hi All,

thanks for your kind feedback

Поздрави от Флоренция

[martindwilson]

ah ben =LOG(400,1.15) is log of 400 to base 1.15 which will give the correct answer also