Engineering Board Exam Reviewer · Binomial Distribution · medium
A binomial experiment has n=20 trials and success probability p=0.3. Find the variance of the number of successes.
- 6
- 1.8
- 2.05
- 4.2
Answer
D. 4.2
Solution
2=npq=20(0.3)(0.7)=4.2.
More Binomial Distribution questions
- A basketball player makes 80% of free throws. In 5 attempts, what is the probability of making at least 4?
- A fair die is rolled 4 times. What is the probability of getting exactly two 6's?
- A fair coin is tossed 6 times. What is the probability of exactly 2 heads?
- A fair coin is tossed 5 times. What is the probability of getting exactly 3 heads?
- A basketball player makes 70% of his free throws. If he attempts 4 free throws, what is the probability that he makes exactly 3?
- A multiple-choice test has 5 questions, each with 4 options (only one correct). If a student guesses randomly on all 5, what is the…
- A binomial distribution has mean 12 and variance 8. Find the number of trials n.
- A fair coin is tossed 10 times. What is the probability that the number of heads is between 4 and 6 inclusive?
- A quiz has 10 multiple-choice questions with 5 choices each. A student guesses every answer. What is the probability of getting at least…
- A process produces 5% defective items. In a random sample of 10 items, what is the probability that none is defective?