#### Answer

$0.031$

#### Work Step by Step

We will use the following formula for the blood alcohol concentration (BAC) of a person who has been drinking.
BAC = (number of oz)(% alcohol)(0.075) / (body weight in lb) - (hr of drinking)(0.015).
We are to determine the BAC for a 190 lb man who has ingested four 12-oz-beers (48 oz) each having 3.2% alcohol, in 2 hours. Estimate to the nearest thousandth.
Number of oz = 48
% alcohol = 3.2
body weight = 190
hr of drinking = 2
We will use the formula:
$BAC=(48)(3.2)(0.075)\div(190)-(2)(0.015)$
$=11.52\div190-2(0.015)$
$=0.061-0.03$
Therefore, the BAC of the person is:
$BAC=0.061-0.03=0.031$