Question

For this question, you need at least 6 decimal places.
An exact answer (fractions) is recommended on both parts, especially the first part since it will be used for the second question.

Baumgartner, Prosser, and Crowell are grading 19

calculus exams on which there is a series of 5 multiple choice questions. Each question has 3

answer choices.

Crowell says, "I bet we should expect at least three exams in which no answer is correct if everyone is just guessing."

First, what is the probability that a student gets no answer correct on the 5

multiple choice questions if he or she guesses randomly with no bias?


What is the probability that there are at least three exams with no answer correct if all 19 students are guessing?
Hint: use your answer from part (a) as the probability of success here. Your trials are the exams (students) now, and we want at least three successes.
You may need to leave your answer as a sum of powers of fractions

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!PLEASE SHOW YOUR WORK. DO NOT JUST PUT AN ANSWER WITH OUT REASONING. i NEED TO BE ABLE TO REPLICATE AND VERIFY YOUR ANSWER. QUESTION SAYS LEAVE IT IN SUM OF POWERS OF FRACTION!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 1