# (1 point) A breathalyser test is used by

Carrillo Valdivia Brian Jafet 2022-04-04

(1 point) A breathalyser test is used by police in an area to determine whether a driver has an excess of alcohol in their blood. The device is not totally reliable: 7 % of drivers who have not consumed an excess of alcohol give a reading from the breathalyser as being above the legal limit, while 10 % of drivers who are above the legal limit will give a reading below that level. Suppose that in fact 14 % of drivers are above the legal alcohol limit, and the police stop a driver at random. Give answers to the following to four decimal places.

Part a)
What is the probability that the driver is incorrectly classified as being over the limit?

Part b)
What is the probability that the driver is correctly classified as being over the limit?

Part c)
Find the probability that the driver gives a breathalyser test reading that is over the limit.

Part d)
Find the probability that the driver is under the legal limit, given the breathalyser reading is also below the limit.

You can still ask an expert for help

Expert Community at Your Service

• Live experts 24/7
• Questions are typically answered in as fast as 30 minutes
• Personalized clear answers

Solve your problem for the price of one coffee

• Available 24/7
• Math expert for every subject
• Pay only if we can solve it

Expert Community at Your Service

• Live experts 24/7
• Questions are typically answered in as fast as 30 minutes
• Personalized clear answers

Solve your problem for the price of one coffee

• Available 24/7
• Math expert for every subject
• Pay only if we can solve it