> There's a reason food service staff is trained to always wash your hands after handling money.

"... to always wash their hands ...", I presume?

That's probably better grammar. I think it works as is though, as their training is "always wash your hands."

Who cares what the median is, though I'm surprised it's not zero.

The average is much higher at 29 mcg, so each gram is a far more reasonable $35k. But the variability is enormous. Choose the right bills and it'll cost you just under $8k (and a fortune in acetonitrile, but you can recover that!).

"Results demonstrated that "92% of the bills were positive for cocaine with a mean amount of 28.75 ± 139.07 micrograms per bill"

https://en.wikipedia.org/wiki/Contaminated_currency

You are going to spend more on solvents, equipment and work to extract that than finding a dealer somewhere.

>so each gram is a far more reasonable $35k. But the variability is enormous. Choose the right bills and it'll cost you just under $8k

I assume a fair portion of the variability is in the bill amount, so the $35k dream is unreachable and the eight thousand bills likely requires mostly hundreds.

> mean amount of 28.75 ± 139.07 micrograms per bill"

Can I get the one with the negative 110 micrograms in it?

The distribution of cocaine is probably not symmetric around the mean. Should that stop us from using statistical methods that rely on assuming it is?