Quick Math/Stat question- - The Lognormal distribution

[theben]

Quick Q,

Does anybody know of the lognormal distribution can ever yield a random variable with a negative value?

for exmaple, can this ever be negative:

LOGN(1.37, 1.28)

Thanks

[Cooker]

No. Its support is [0,+infinity). I think it is generally used for distributions where you expect there to be no chance of negative values (for instance economic models where money can't be borrowed below net assets). This is not my area of expertise, but I am fairly sure this is correct.

LOGN(x,y) is never negative (maybe for complex x and y but this would be well outside the purpose of the distribution). Further, x and y are both restriced to positive values.

[BeerMoney]

The log normal means that if you toof the log of the x's you'd get a normal distribution, and since you can't take the log of a negative number, this distribution can't have any negative x values.