Hi, I have a few statistics questions.

Five friends took the final exam and the probability that each of them would get an A is 1/2. Use Binomial distribution to answer the following questions.

We are interested in total number of As among these five friends.

17. What are the n and p in this (binomial) model?

• a. n=5 p=1/2
• b. n=A and p=1/5
• c. n=5 p=1/5 and k=0,1,2,3,4,..
• d. None of the above.

18. What is the probability that 2 out of 5 friends got A's on the exam?

• a.
• b. 0.046875
• c. 0.3125
• d. None of the above.

19. Which of these is the most likely to happen?

• a. None of the friends got an A.
• b. All of them got As.
• c. Only one friend got an A.
• c. Only two friends got A's.

I believe the first one is A, but I have no clue on the other 2.