Final answer:
The risk of causing an accident is 3.25 times as great if the driver has a BAC of .15%.
Step-by-step explanation:
The risk of causing an accident is 3.25 times as great if the driver has a BAC of .15%. This means that the probability of causing an accident is significantly higher when the driver has a blood alcohol concentration (BAC) of .15% compared to a driver with no alcohol in their system.