UPDATE: Coffee Grounds has more on the subject.
.4% X 4 = 1.6%
.4% X 5 = 2%
She said who couldn't divide by 4.
So, who is innumerate, the pharmacist or the patient?
Posted by: bruce quaintance on November 13, 2003
Bruce, I'm not going to call you innumerate, but I suggest you think through what a "four-to-one dilution" is before you fill any prescriptions. Julie is correct.
Posted by: Moira on November 14, 2003
Check out my post and the ensuing comment thread on this subject. You may feel a bit better. FYI, "Suzette" is a 50-something RN ("Real Nurse") with some expertise in these matters.
http://coffeegrounds.typepad.com/blog/2003/11/can_i_get_an_eh.html
Posted by: The Proprietor on November 14, 2003
Moira,
You forced me to do some remedial study of ratios online, and you are correct. A 4:1 ratio does result in an 80% dilution, yielding a .4% result. My hopes of someday wearing a white labcoat are dashed.
Posted by: bruce quaintance on November 15, 2003
Bruce - Nah, I wouldn't worry about it. I'd guess that even most reasonably numerate people who aren't familiar with doing dilutions would calculate a one-quarter, not a one-fifth strength solution. Even some in white coats.
Prop - thanks for the link. Btw, I turned the html back on, so link 'em if you got 'em, efferybahdy.
Posted by: Moira on November 16, 2003