Question
upstudy study bank question image url

A Gallup poll of 1236 adults showed that \( 12 \% \) of the respondents believe that it is bad luck to walk under a ladder. Consider the probability that among 30 randomly selected people from the 1236 who were polled, there are at least 2 who have that belief. Given that the subjects surveyed were selected without replacement, the events are not independent. Can the probability be found by using the binomial probability formula? Why or why not? Choose the correct answer below. A. No. The selections are not independent, and the \( 5 \% \) guideline is not met. B. No. The selections are not independent. C. Yes. Although the selections are not independent, they can be treated as being independent by applying the \( 5 \% \) guideline. D. Yes. There are a fixed number of selections that are independent, can be classified into two categories, and the probability of success remains the same.

Ask by Wells Warner. in the United States
Feb 13,2025

Real Tutor Solution

Tutor-Verified Answer

Answer

The probability can be found using the binomial formula because the sample size is less than 5% of the total population, making the selections approximately independent.

Solution

The answer is C. Even though the selections are done without replacement and are therefore not technically independent, the sample size of 30 is only about 2.4% of the total population of 1236 (which is below the 5% threshold commonly used). When the sample is less than 5% of the population, the probability of success remains nearly constant from one selection to the next, so the events may be treated as approximately independent. This allows the use of the binomial probability formula as an acceptable approximation in this case.

Reviewed and approved by the UpStudy tutoring team

error msg
Explain
Simplify this solution

Mind Expander

To answer your question, let’s dive deep into the topic! The scenario you provided involves selecting individuals from a finite population, specifically the 1236 adults surveyed. The key here is the assumption of independence in probabilities for binomial calculations. While the selections are indeed not independent because they are made without replacement, you could use the binomial probability formula if the \( 5\% \) guideline is satisfied. This guideline suggests that if the sample size is less than \( 5\% \) of the population, the changes made to the probabilities are negligible. Since \( 30 \) is less than \( 5\% \) of \( 1236 \), the correct answer is C: Yes. Although the selections are not independent, they can be treated as being independent by applying the \( 5 \% \) guideline. Now, let’s explore some related engaging nuggets! Did you know that the belief in superstitions, like the bad luck of walking under ladders, has been present for centuries? This particular superstition can be traced back to ancient Egypt, where the ladder's triangular shape was associated with the pyramid symbol—representing the Holy Trinity. Passing under a ladder was believed to break that sacred triangle, thus invoking bad luck or angering the gods. Fascinating, right? In practical terms, understanding probability in everyday life can help quell irrational fears. For instance, knowing that merely walking under a ladder doesn't influence your luck can empower you to challenge and change those nagging superstitions. Whether you chuckle at bad luck mishaps or make choices based on them, understanding the math behind it can often make one feel more in control. Why not give it a shot and decide to walk under that ladder!

Related Questions

Latest Probability Questions

Try Premium now!
Try Premium and ask Thoth AI unlimited math questions now!
Maybe later Go Premium
Study can be a real struggle
Why not UpStudy it?
Select your plan below
Premium

You can enjoy

Start now
  • Step-by-step explanations
  • 24/7 expert live tutors
  • Unlimited number of questions
  • No interruptions
  • Full access to Answer and Solution
  • Full Access to PDF Chat, UpStudy Chat, Browsing Chat
Basic

Totally free but limited

  • Limited Solution
Welcome to UpStudy!
Please sign in to continue the Thoth AI Chat journey
Continue with Email
Or continue with
By clicking “Sign in”, you agree to our Terms of Use & Privacy Policy