1.) When doing blood testing for a viral infection, the procedure can be made mo
ID: 3069669 • Letter: 1
Question
1.) When doing blood testing for a viral infection, the procedure can be made more efficient and less expensive by combining partial samples of different blood specimens. If samples from five people are combined and the mixture tests negative, we know that all five individual samples are negative. Find the probability of a positive result for five samples combined into one mixture, assuming the probability of an individual blood sample testing positive for the virus is 0.02.
Round the answer to four decimal place accuracy.
2.) Every cereal box has a gift inside, but you cannot tell from the outside what the gift is. The store manager assures you that 15 of the 60 boxes on the shelf have the secret decoder ring. The other 45 boxes on the shelf have a different gift inside. If you randomly select two boxes of cereal from the shelf to purchase, what is the probability that BOTH of them have the secret decoder ring?
3.) In a large population, 59 % of the people have been vaccinated. If 4 people are randomly selected, what is the probability that AT LEAST ONE of them has been vaccinated?
Give your answer as a decimal to at 4 places.
4.) An experiment consists of first rolling a die and then tossing a coin:
Let A be the event that either a 3 or 4 is rolled first, followed by landing a head on the coin toss.
P(A) = Present your answer as a decimal rounded to four decimal places.
Explanation / Answer
1.) Probability of an individual blood sample testing positive for the virus is 0.02
A mixture contains blood sample of 5 people.
P(Mixture tests positive) = (0.02)5
= 32 x 10-10
2.) We randomly select 2 boxes out of 60 cereal boxes.
P(Both of them have secret decoder ring)= (2C15)/(2C60)
=0.0593
3.) P(person is vaccinated) = 0.59
P(person not being vaccinated) = 0.41
4 people are randomly selected.
Let x be the no. of persons vaccinated.
P(atleast one of them has been vaccinated) = P(X>=1)
= 1 - P(X=0)
= 1 - (0.41)4
P(atleast one of them has been vaccinated) = 0.9717
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.