Here's the "short story"on the ethanol content testing- a specific amount of fuel is taken as the sample size and a specific amount of water is added to the sample. Since the water bonds with the ethanol, the amont of water they measure from the sample that they "get back" determines the percentage of ethanol in the fuel. Amounts as high as 19% have been taken from local fuel samples.
(There was a point in my education where I lost interest in chemistry just as it started to involve math. This brings back memories...)
That's the story- does it make any sense to anyone?
Sure does....and if you don't know what the original water content was of the sample, you don't really know the result now do you? Sorry, I do know some chemistry. Good story however. If this 'test' is happening in the garage versus being sent to a lab - which I doubt - you may as well treat the problem with sea foam...