Section 3.4:

5, 6, 7, 12

Section 3.5:

9, 10, 11, 12, 13

Additional Problem:

Assume that from 2 AM to 3 AM, 1 in 1000 drivers are driving drink: they have a 0.08% blood alcohol concentration (BAC) or higher. Police stop all cars at a sobriety checkpoint using a breathalyzer. A positive reading on the breathalyzer is taken by the police to indicate drunkenness. An individual with a BAC greater than 0.08% will always test positive on the breathalyzer. An individual with a BAC less than 0.08% tests positive on the breathalyzer 5% of the time.

Question: A driver at the sobriety checkpoint tests positive on the breathalyzer. What is the probability that the driver has a BAC greater than 0.08%, i.e. is driving drunk?

Hint: Use the natural frequencies diagram method we used in class.