Conditional Probability Bayes

A virus has infected 1.8% of a population. A test detects this virus 95% of the time when it is actually present, but it returns a false positive 3% of the time when the virus is not present.
If a person selected at random from this population tests positive for the virus, what is the probability that this person is actually infected? [Round to the nearest percent.]

• 37%

• 63%

• 34%

• 66%

83% of a certain airline's flights depart on time. Of these flights, 90% also arrive on time. 30% of flights from this airline that depart late manage to make up time in the air to still arrive on time.
You see a flight from this airline arriving on time. What is the probability that it departed on time?

• 0.9361

• 0.9608

• 0.9721

• 0.8532

Naina receives emails that consists of 18% spam of those emails. The spam filter is 93% reliable i.e., 93% of the mails it marks as spam are actually a spam and 93% of spam mails are correctly labelled as spam. If a mail marked spam by her spam filter, determine the probability that it is really spam.

• a) 50%

• b) 84%

• c) 39%

• d) 63%

• 1
• 2
• 3
• 4

-the likelihood of an event or outcome occurring, based on the occurrence of a previous event or outcome

• mean

• median

• conditional probability

• probability

A box contains 3 brand A batteries and 7 brand B batteries. 30% of brand A batteries are faulty and 40% of brand B batteries are faulty. A battery is selected at random and then checked to see if it is faulty. What is the probability that a not faulty brand A battery is selected?

• 0.21

• 0.09

• 0.28

• 0.25

the likelihood of an event or outcome occurring, based on the occurrence of a previous event or outcome

• mean

• median

• conditional probability

• probability

The probability of an event occuring given that another event has already occured is called

• Independent Events

• Conditional Probability

• Dependent Events

• FPC

What is the probability that a female is chose given they like a Toyota?

• .525

• .4627

• .6774

• .3143

If P(A) = 0.20, P(B|A)=0.60 and P(B|A')=0.25, then P(A|B) = 

• 0.3750

• 0.7059

• 0.6250

• 0.2941