love your article and it completely explains this so-called phenomenon...

two technical questions,

having read about this phenomenon, i started doing work on my own but hit a wall within seconds,

1) regarding a geometric mean, what about negative returns? i understand you can use (1+R/100), but it seems if the numbers are all positive, people use R instead.. will this theoretically give same result?.......... can you use sqrt(R^n) somehow with negative numbers?

2) if i use norm.inv (norminv?) in excel, will that solve the problem? i'm thinking no as that's normal, not lognormal

thx in advance