Theme: Risk Assessment 100 Foundations of Mathematical Reasoning, In-Class Activities, Lesson 14.C Lesson 14 Part C, Blood alcohol content Blood alcohol content (BAC) is a measurement of how much alcohol is in someone's blood. It is usually measured as a percentage, so a BAC of 0.3% is three-tenths of 1%. That is, there are 3 grams of alcohol for every 1,000 grams of blood. A BAC of 0.05% impairs reasoning and the ability to concentrate. A BAC of 0.30% can lead to a blackout, shortness of breath, and loss of 1) BAC is usually determined by a breathalyzer, urinalysis, or blood test. However, Swedish physician E.M.P. Widmark developed the following equation for estimating an individual's BÁC. This formula is widely used by forensic 2) biadder control. In most states. the legal limit for driving is a BAC of 0.08%.31 3 scientists:32 2.84.N B =-0.015-t + Credit: zstock/Fotolia W•g Objectives for the lesson You will understand that: O The location of a variable is important to its effect on the size of an expression. You will be able to: O Explicitly write out order of operations to evaluate a given formula. The variables in the formula are defined as: B = percentage of BAC N = number of "standard drinks" (N should be at least 1) (A standard drink is one 12-ounce beer, one 5-ounce glass of wine, or one 1.5-ounce siot of liquor.) W = weight in pounds %3D g = gender constant, 0.68 for men and 0.55 for women t%3Dnumber of hours since the first drink 31 Blood alcohol content. In Wikipedia. Retrieved June 7, 2014, from http://en.wikipedia.org/wiki/ Blood alcohol_content. Note that different countries measure BAC in different ways involving mass and 32 Gullberg, R. G. (2007, August). Estimating the uncertainty associated with Widmark's equation as volume. commonly applied in forensic toxicology. Paper presented at the T2007 Conference. Retrieved June 7, 2014, from www.icadts2007.org/print/108widmarksequation.pdf. Copyright © 2016, The Charles A. Dana Center at the University of Texas at Austin Foundations of Mathematical Reasoning, In-Class Activities, Lesson 14.C 101 Look at the right side of the equation, How do the variables and their location make sense 1) in calculating BAC? For example, based on their locations, which variables will make BAC larger? Which will make it smaller? Consider the case of a male student who has five beers and weighs 180 pounds. Simpliry 2) the equation as much as possible for this case. What variables are still unknown in the equation? 3) Using your simplified equation, find the estimated BAC for this student one, three, and five hours after his first drink. What patterns do you notice in the data? 4) Record the sequence of steps you took to get from "time" to BAC. Be specific. For example, did you multiply, add, subtract, etc.? What values and in what order? unnal be 1o sonetip elsm Teuc Juode ooegs od hebo bns as