Each of the questions in a certain multiple-choice test has four answers, exactly one of which...

Each of the questions in a certain multiple-choice test has four answers, exactly one of which is correct. The probability that a test taker knew the answer to a question they answered correctly is 12. What proportion of the questions test takers answer correctly? Assume that a test taker always answer correctly to a question they know, and randomly pick an answer to a question they do not know.

Solutions

Expert Solution

orchestra answered 1 year ago

Next > < Previous

Related Solutions

For each question on a multiple-choice test, there are five possible answers of which exactly one...

For each question on a multiple-choice test, there are five possible answers of which exactly one is correct for each question. Assume there are 10 questions on the test and a student selects one answer for each question at random. Let X be the number of correct answers he or she gets. a) How is X distributed? (Specify the values of the corresponding parameters). b) Find P(X < 6) and P(X = 6). c) Find E(X) and V ar(X). 2....

On a multiple choice test with 18 questions, each question has four possible answers, one of...

On a multiple choice test with 18 questions, each question has four possible answers, one of which is correct. For students who guess at all answers, find the variance for the number of correct answers.

A multiple choice test consists of 60 questions. Each question has 4 possible answers of which...

A multiple choice test consists of 60 questions. Each question has 4 possible answers of which one is correct. If all answers are random guess, estimate the probability of getting at least 20% correct.

Consider a multiple-choice examination with 50 questions. Each question has four possible answers.

Consider a multiple-choice examination with 50 questions. Each question has four possible answers. Assume that a student who has done the homework and attended lectures has a 65% chance of answering any question correctly. (Round your answers to two decimal places.) (a) A student must answer 43 or more questions correctly to obtain a grade of A. What percentage of the students who have done their homework and attended lectures will obtain a grade of A on this multiple-choice examination?...

A standardized test consists of 100 multiple-choice questions. Each question has five possible answers, only one...

A standardized test consists of 100 multiple-choice questions. Each question has five possible answers, only one of which is correct. Four points are awarded for each correct answer. To discourage guessing, one point is taken away for every answer that is not correct (this includes answers that are missing). The company that creates the test has to understand how well a student could do just by random guessing. Suppose a student answers each question by picking one of the five...

A student answers a multiple choice examination with two questions that have four possible answers each....

A student answers a multiple choice examination with two questions that have four possible answers each. Suppose that the probability that the student knows the answer to a question is 0.80 and the probability that the student guesses is 0.20. If the student guesses, the probability of guessing the correct answer is 0.25. The questions are independent, that is, knowing the answer on one question is not influenced by the other question. (a) What is the probability that the both...

A multiple choice test has 27 questions with four choices each. The examinee gets 3 for...

A multiple choice test has 27 questions with four choices each. The examinee gets 3 for each right asnwer and -1 for each wrong answer. If the examinee decided to randonly choose all the asnwers, what is her expecteed score? A) 0 B) 1 C) 9 D) -3

A multiple-choice test has 48 questions, each with four response choices. If a student is simply...

A multiple-choice test has 48 questions, each with four response choices. If a student is simply guessing at the answers, 1. What is the probability of guessing correctly for any individual question? 2. On average, how many questions would a student answer correctly for the entire test? 3. What is the probability that a student would get more than 15 questions correct? p(more than 15 answers correct) 4. What is the probability that a student would get 15 or more...

Consider a multiple-choice examination with 50 questions. Each question has four possible answers. Assume that a...

Consider a multiple-choice examination with 50 questions. Each question has four possible answers. Assume that a student who has done the homework and attended lectures has a 65% chance of answering any question correctly. (Round your answers to two decimal places.) (a)A student must answer 44 or more questions correctly to obtain a grade of A. What percentage of the students who have done their homework and attended lectures will obtain a grade of A on this multiple-choice examination? Use...

Consider a multiple-choice examination with 50 questions. Each question has four possible answers. Assume that a...

Consider a multiple-choice examination with 50 questions. Each question has four possible answers. Assume that a student who has done the homework and attended lectures has a 75% probability of answering any question correctly. A student must answer 43 or more questions correctly to obtain a grade of A. What percentage of the students who have done their homework and attended lectures will obtain a grade of A on this multiple-choice examination? A student who answers 35 to 39 questions...

Subjects