Chapter 14.1, Problem 19PS

When a person in California renews the registration for an automobile, the bar graph shown in Figure 14.24 is included with the bill.

Use this bar graph to answer the questions in Problems 18–23. The following statement is included with the graph:

There is no safe way to drive after drinking. These charts show that a few drinks can make you an unsafe driver. They show that drinking affects your BLOOD ALCOHOL CONCENTRATION (BAC). The BAC zones for various numbers of drinks and time periods are printed in white, gray, and red. HOW TO USE THESE CHARTS: First, find the chart that includes your weight. For example, if you weigh $160$ lbs., use the $“150to169”$ chart. Then look under “Total Drinks” at the $“2”$ on this $“150to169”$ chart. Now look below the $“2”$ drinks, in the row for 1 hour. You’ll see your BAC is in the gray shaded zone. This means that if you drive after $2$ drinks in 1 hour, you could be arrested. In the gray zone, your chances of having an accident are $5$ times higher than if you had no drinks. But if you had $4$ drinks in 1 hour, your BAC would be in the red shaded area. . . and your chances of having an accident $25$ times higher.

Suppose that you weigh $115$ pounds and that you have four drinks in $3$ hours. If you then drive, how much more likely are you to have an accident than if you had refrained from drinking?