Everyone knows that alcohol impairs reaction time. For example, one study indicates that reaction time at a blood alcohol concentration of 0.08% doubles from 1.5 to 3 seconds. Your job is to compile some probabilities based on existing data to help convince people that it is a really bad idea to get behind the wheel of a car after consuming alcohol. It is also a bad idea to get into a car with an individual who has had a few drinks.
Go to the Fatality Analysis Reporting System Encyclopedia, which is online at the National Highway Traffic Safety Administration website (under Data). This encyclopedia contains records of all fatal car crashes for any given year. Click Run a Query Using the FARS Web-Based Encyclopedia. Click Query FARS data. You might consider reading the documentation provided to get a sense as to the type of data that can be obtained. Select a year you wish to analyze and click Submit.
You should see a table with variables that can be considered as they relate to fatal vehicle crashes. For example, if you want to determine the probability that a crash resulted from driver alcohol involvement, you could check the Driver Alcohol Involvement box. Then click Submit. In the drop-down menu, you can fine-tune the data obtained. Click Univariate Tabulation. The next screen allows for further refinement. Click Submit, and you will have the data for the current year. Compile a few probabilities for univariate analysis.
Next, consider relations among two variables. For example, is there a relation between gender and driver alcohol involvement? Check both variables and click Submit. Again, you can fine-tune the data obtained. Once this is complete, select Cross Tabulation. Now choose the appropriate column and row variables to create a contingency table and click Submit. Develop a few conditional probabilities to see the relation between your two variables. Are they independent? If not, what does the dependency tell us?
Write a report, complete with the probabilities showing variable dependencies, that can be used to convince people of the dangers of mixing alcohol consumption with driving.