Q16A certain virus infects one in every 300 people. A test used to detect the virus in a person is positive 80% of the time if the person has the virus and 5% of the time if the person does not have the virus. (This 5% result is called a false positive.) Let A be the event "the person is infected" and B be the event "the person tests positive".

a) Find the probability that a person has the virus given that they have tested positive, i.e. find P(A|B). Round your answer to the nearest tenth of a percent and do not include a percent sign.

P(A|B)=__%

b) Find the probability that a person does not have the virus given that they test negative, i.e. find P(A'|B'). Round your answer to the nearest tenth of a percent and do not include a percent sign.

P(A'|B') =___%

Q17

A company estimates that 0.4% of their products will fail after the original warranty period but within 2 years of the purchase, with a replacement cost of $50.

If they offer a 2 year extended warranty for $7, what is the company's expected value of each warranty sold?

Q18

Use the Empirical Rule to answer the questions below:

The distribution of weights for newborn babies is approximately normally distributed with a mean of 7.6 pounds and a standard deviation of 0.6 pounds.

1. What percent of newborn babies weigh more than 8.2 pounds?%

2. The middle 95% of newborn babies weigh between___and____pounds.

3. What percent of newborn babies weigh less than 6.4 pounds?___%

4. Approximately 50% of newborn babies weigh more than____pounds.

5. What percent of newborn babies weigh between 7 and 9.4___ pounds?