Question
upstudy study bank question image url

(1) Use the normal approximation to the binomial to find the probability for \( n=10, p=0.5 \), and \( X \geq 7 \). Use \( \Theta \) The Standard Normal Distribution Table. Round \( z \) - value calculations to 2 decimal places and final answer to 4 decimal places. The probability is

Ask by Owen Crawford. in the United States
Mar 11,2025

Upstudy AI Solution

Tutor-Verified Answer

Answer

The probability is approximately 0.1711.

Solution

We are given a binomial random variable \( X \) with parameters \( n = 10 \) and \( p = 0.5 \). We want to approximate \[ P(X \geq 7) \] using the normal approximation to the binomial. The steps are as follows. 1. The mean \( \mu \) and variance \( \sigma^2 \) of the binomial distribution are given by \[ \mu = np \quad \text{and} \quad \sigma^2 = np(1-p). \] For \( n = 10 \) and \( p = 0.5 \): \[ \mu = 10 \times 0.5 = 5, \quad \sigma^2 = 10 \times 0.5 \times 0.5 = 2.5. \] Thus, the standard deviation is \[ \sigma = \sqrt{2.5} \approx 1.58. \] 2. We use the continuity correction for the inequality \( X \geq 7 \). Since the normal approximation is continuous, we approximate \[ P(X \geq 7) \approx P\left( X \geq 6.5 \right). \] 3. Standardize using the transformation \[ z = \frac{x - \mu}{\sigma}. \] For \( x = 6.5 \): \[ z = \frac{6.5 - 5}{1.58} \approx \frac{1.5}{1.58} \approx 0.95. \] 4. Now, we find the probability using the standard normal distribution: \[ P(Z \geq 0.95) = 1 - \Phi(0.95). \] From the standard normal distribution table, we have \[ \Phi(0.95) \approx 0.8289. \] Thus, \[ P(Z \geq 0.95) \approx 1 - 0.8289 = 0.1711. \] 5. Rounding the final answer to four decimal places, we get: \[ \boxed{0.1711}. \]

Answered by UpStudy AI and reviewed by a Professional Tutor

error msg
Explain
Simplify this solution

Bonus Knowledge

To use the normal approximation to the binomial distribution, we first need to compute the mean \( \mu \) and standard deviation \( \sigma \). From your parameters, \( n = 10 \) and \( p = 0.5 \): \[ \mu = n \cdot p = 10 \cdot 0.5 = 5 \] \[ \sigma = \sqrt{n \cdot p \cdot (1 - p)} = \sqrt{10 \cdot 0.5 \cdot 0.5} = \sqrt{2.5} \approx 1.58 \] Since \( X \) is a discrete variable, we can use continuity correction. We want to find \( P(X \geq 7) \), which can be approximated by: \[ P(Z \geq 6.5) \] We convert this using the z-score formula: \[ z = \frac{X - \mu}{\sigma} = \frac{6.5 - 5}{1.58} \approx \frac{1.5}{1.58} \approx 0.95 \] Now, we look up \( z = 0.95 \) in the standard normal distribution table, which gives us a probability of \( P(Z < 0.95) \approx 0.8264 \). Therefore, the probability we want is: \[ P(Z \geq 0.95) = 1 - P(Z < 0.95) = 1 - 0.8264 = 0.1736 \] Thus, rounded to four decimal places, the probability is: **0.1736**

Related 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