# statistics

posted by .

A multiple choice exam has 20 questions; there are four choices for each question.
A student guesses the answer to every question. Find the chance that he guesses correctly between four and seven times.
Find the minimum score the instructor can set so that the probability that a student will pass just by guessing is 20% or less.

## Similar Questions

1. ### Statistics

A student is taking a multiple-choice exam with 16 questions. Each question has five alternatives. If the student guesses on 12 of the questions, what is the probability she will guess at least 8 correct?
2. ### Binomial Distribution

A biology quiz consists of twelve multiple-choice questions. Eight must be answered correctly to receive a passing grade. If each question has five possible answers, of which only one is correct, what is the probability that a student …
3. ### Finite Math

A biology quiz consists of 10 multiple -choice questions. 7 must be answered correctly to receive a passing grade. If each question has 4 possible answers, of which only one is correct, what is the probability that a student who guesses …
4. ### Statistics

A 50-question true-false exam is given. Each correct answer is worth 10 points. Consider an unprepared student who randomly guesses on each question. In your solution, please be sure to show the exact steps you used to arrive at the …
5. ### Stats

A student takes a 32 question multiple choice exam but did not study and randomly guesses each answer. Each question has three possible choices for the answer. Find the probability that the student guesses more than 75% of the questions …
6. ### Statistics

A student makes random guesses on 6 multiple-choice questions. One of the 5 choices in each question is correct. What is the probability that the student will get at most 4 answers right?
7. ### Statistics

A student guesses blindly on a 20-question multiple choice test. If each question has 4 answer choices (only one of which is correct), what is the probability that the student will answer exactly 10 questions correctly?
8. ### Math

A multiple - choice quiz contains 5 questions with 4 choices for each answer. A student passes the quiz if they get at least an 80% on the quiz . If a student guesses on every question , find the probability that she passes the quiz …
9. ### stats

A multiple choice test consists of four questions. Each question has five possible answers of which only one is correct. A student guesses on every question. Find the probability distribution of X, the number of questions she answers …