2) A normal distribution has a mean of µ = 10 with o = 3.5. What proportion of the scores in this distribution are greater than X = 5.5?

MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
icon
Related questions
Question
**Problem Statement:**

A normal distribution has a mean (\(\mu\)) of 10 and a standard deviation (\(\sigma\)) of 3.5. What proportion of the scores in this distribution are greater than \(X = 5.5\)? 

**Solution:**

To find the proportion of scores greater than \(X = 5.5\), we can use the Z-score formula:

\[ Z = \frac{X - \mu}{\sigma} \]

**Steps:**

1. **Calculate the Z-score for \(X = 5.5\):**

   \[
   Z = \frac{5.5 - 10}{3.5} = \frac{-4.5}{3.5} \approx -1.29
   \]

2. **Find the Probability:**

   We look up the Z-score of -1.29 in the standard normal distribution table, or use a calculator, to find the probability that \(X \leq 5.5\).

   - Probability (\(X \leq 5.5\)) ≈ 0.0985

3. **Calculate the Proportion Greater Than \(X = 5.5\):**

   \[
   \text{Proportion} (X > 5.5) = 1 - \text{Probability} (X \leq 5.5) = 1 - 0.0985 \approx 0.9015
   \]

**Conclusion:**

Approximately 90.15% of the scores in this distribution are greater than \(X = 5.5\).

**Graphical Representation:**

This solution can be visualized using a bell curve where the area under the curve to the right of \(X = 5.5\) represents the proportion of the distribution greater than this value. The mean \(\mu = 10\) is the center of the distribution, and the standard deviation \(\sigma = 3.5\) defines the spread.
Transcribed Image Text:**Problem Statement:** A normal distribution has a mean (\(\mu\)) of 10 and a standard deviation (\(\sigma\)) of 3.5. What proportion of the scores in this distribution are greater than \(X = 5.5\)? **Solution:** To find the proportion of scores greater than \(X = 5.5\), we can use the Z-score formula: \[ Z = \frac{X - \mu}{\sigma} \] **Steps:** 1. **Calculate the Z-score for \(X = 5.5\):** \[ Z = \frac{5.5 - 10}{3.5} = \frac{-4.5}{3.5} \approx -1.29 \] 2. **Find the Probability:** We look up the Z-score of -1.29 in the standard normal distribution table, or use a calculator, to find the probability that \(X \leq 5.5\). - Probability (\(X \leq 5.5\)) ≈ 0.0985 3. **Calculate the Proportion Greater Than \(X = 5.5\):** \[ \text{Proportion} (X > 5.5) = 1 - \text{Probability} (X \leq 5.5) = 1 - 0.0985 \approx 0.9015 \] **Conclusion:** Approximately 90.15% of the scores in this distribution are greater than \(X = 5.5\). **Graphical Representation:** This solution can be visualized using a bell curve where the area under the curve to the right of \(X = 5.5\) represents the proportion of the distribution greater than this value. The mean \(\mu = 10\) is the center of the distribution, and the standard deviation \(\sigma = 3.5\) defines the spread.
Expert Solution
steps

Step by step

Solved in 3 steps with 7 images

Blurred answer
Similar questions
Recommended textbooks for you
MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
Probability and Statistics for Engineering and th…
Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning
Statistics for The Behavioral Sciences (MindTap C…
Statistics for The Behavioral Sciences (MindTap C…
Statistics
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning
Elementary Statistics: Picturing the World (7th E…
Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON
The Basic Practice of Statistics
The Basic Practice of Statistics
Statistics
ISBN:
9781319042578
Author:
David S. Moore, William I. Notz, Michael A. Fligner
Publisher:
W. H. Freeman
Introduction to the Practice of Statistics
Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman