In: Statistics and Probability
Steve is about to write a test with 10 true or false questions and 15 multiple choice questions. Steve has been studying hard so we’ll give a 75% chance of getting any of the 25 questions right. Assume all the questions are independent of each other.
(a) (2 points) What is the probability that Steve gets exactly two thirds of the multiple choice questions right?
(b) (3 points) What is the probability that Steve gets exactly half the true or false questions right AND gets exactly two thirds of the multiple choice questions right?
(c) (4 points) If the test was all multiple choice (i.e. 25 questions), use the normal approximation to estimate the probability that Steve get between 15 and 20 questions right.