Math Problem Statement
A student takes a 10 question multiple choice quiz- each question having 4 choices. Suppose a student randomly picks an answer for each question. Find the following. What is the chance (as a percentage) that student gets more than 4 questions correct?
Solution
To solve this problem, we need to calculate the probability that a student randomly guesses more than 4 questions correctly on a 10-question multiple choice quiz, where each question has 4 possible choices. Since the student is guessing, the probability of guessing any single question correctly is , and the probability of guessing incorrectly is .
This situation follows a binomial distribution because each question has two possible outcomes: correct or incorrect. The binomial probability formula is:
Where:
- (number of trials, i.e., questions),
- is the number of correct answers (this varies),
- (the probability of success, i.e., getting a question right).
We are asked to find the probability that the student gets more than 4 questions correct, i.e., . This is equivalent to calculating the sum of the probabilities for getting 5, 6, 7, 8, 9, and 10 correct answers:
I will now calculate this probability.The probability that the student gets more than 4 questions correct by randomly guessing is approximately 7.81%.
Would you like further details on how this was calculated or any other clarification?
Here are some related questions for practice:
- What is the probability of getting exactly 4 questions correct?
- What is the probability of getting all 10 questions correct?
- What is the expected number of correct answers in this quiz?
- How does the probability change if the quiz has 20 questions?
- What is the variance of the number of correct answers in this scenario?
Tip: In binomial distributions, the expected value is calculated as , where is the number of trials and is the probability of success.
Ask a new question for Free
By Image
Drop file here or Click Here to upload
Math Problem Analysis
Mathematical Concepts
Probability
Binomial Distribution
Formulas
P(X = k) = (n choose k) * p^k * (1 - p)^(n - k)
P(X > 4) = P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10)
Theorems
Binomial Theorem
Suitable Grade Level
Grades 9-12
Related Recommendation
Binomial Distribution: Probability of Correct Answers on a 10-Question Multiple Choice Quiz
Binomial Distribution for Multiple-Choice Test with Random Guessing
Probability of Answering At Least 7 Questions Correctly in a 21-Question Quiz
Binomial Probability: Getting Exactly 4 Correct Answers on a 12-Question Test
Binomial Probability for 6 Correct Answers in a 20-Question Multiple Choice Test