Stats
posted by Collie .
Richard has just been given a 4question multiplechoice quiz in his history class. Each question has five answers, of which only one is correct. Since Richard has not attended class recently, he doesn't know any of the answers. Assuming that Richard guesses on all four questions, find the indicated probabilities. (Round your answers to three decimal places.)
(a) What is the probability that he will answer all questions correctly?
.
(b) What is the probability that he will answer all questions incorrectly?
.
(c) What is the probability that he will answer at least one of the questions correctly? Compute this probability two ways. First, use the rule for mutually exclusive events and the probabilities shown in the binomial probability distribution table.
.
Then use the fact that P(r ≥ 1) = 1 − P(r = 0).
.
Compare the two results. Should they be equal? Are they equal? If not, how do you account for the difference?
They should not be equal, but are equal. They should be equal, but may not be due to table error. They should be equal, but may differ slightly due to rounding error. They should be equal, but differ substantially.
(d) What is the probability that Richard will answer at least half the questions correctly?
.
Respond to this Question
Similar Questions

Statistics
Richard has been given a 5question multiplechoice quiz in his history class. Each question has four answers, of which only one is correct. Since Richard has not attended the class recently, he does not know any of the answers. The … 
statistics
Richard has been given a 5question multiplechoice quiz in his history class. Each question has three answers, of which only one is correct. Since Richard has not attended the class recently, he doesn't know any of the answers. The … 
Statistics
On a very short quiz, there is one multiple choice question with 5 possible choices (a, b, c, d, e) and one true or false question. Assume you are taking the quiz but do not have any idea what the correct answer is to either question. … 
elementary stats
On a multiple choice test with 11 questions, each question has four possible answers, one of which is correct. For students who guess at all answers, find the mean for the number of correct answers. 
Statistic
There are two independent multiplechoice quizzes where quiz 1 has eight questions and quiz 2 has 15 questions. Each question in the first quiz has four choices and each question in the second quiz has five choices. Suppose a student … 
statistic and probability
There are two independent multiplechoice quizzes where quiz 1 has eight questions and quiz 2 has 15 questions. Each question in the first quiz has four choices and each question in the second quiz has five choices. Suppose a student … 
math
A student takes a multiple choice quiz with 12 questions and 5 alternatives per question. Unfortunately, this student has no idea what any of the answers are, so he randomly selects an alternative for each question on the exam. Using … 
Statistical concept 689599.7
1. A student taking a midterm exam in Ancient History comes to two questions pertaining to a lecture that he missed, and so he decides to take a random guess on both questions. One question is truefalse and the other is multiple choice … 
Stat HW for.
1. A student taking a midterm exam in Ancient History comes to two questions pertaining to a lecture that he missed, and so he decides to take a random guess on both questions. One question is truefalse and the other is multiple choice … 
math data management
a multiple choice quiz has 10 questions. each question has five possible answers.carman is certain that she knows the correct answers for questions 1 and 4. if she guesses the other questions, determine the probability that she gets …