Assuming that the heights of college women are normally distributed with mean 67 inches and standard deviation 2 inches, what percentage of women are taller than 61 inches? 97.7% 99.9% 15.9% 50.0% 0.1%

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
Please answer quickly! Thanks
### Understanding Normal Distribution and Heights of College Women

**Problem Statement:**

Assuming that the heights of college women are normally distributed with a mean of 67 inches and a standard deviation of 2 inches, what percentage of women are taller than 61 inches?
 
**Possible Answers:**
- 97.7%
- 99.9%
- 15.9%
- 50.0%
- 0.1%

**Explanation:**

To solve this problem, we need to use the properties of the normal distribution. According to the empirical rule (also known as the 68-95-99.7 rule), for a normal distribution:

1. About 68% of values fall within one standard deviation of the mean.
2. About 95% of values fall within two standard deviations of the mean.
3. About 99.7% of values fall within three standard deviations of the mean.

The z-score formula for a given value \(X\) in a normal distribution is:

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

Where:
- \( \mu \) is the mean
- \( \sigma \) is the standard deviation
- \( X \) is the value for which we are calculating the z-score

For \(X = 61\):
\[ Z = \frac{61 - 67}{2} = \frac{-6}{2} = -3 \]

A z-score of -3 means that 61 inches is 3 standard deviations below the mean. Looking at standard normal distribution tables, a z-score of -3 corresponds to a percentile of about 0.1%, meaning 0.1% of the women are shorter than 61 inches. Therefore, the percentage of women taller than 61 inches is approximately 100% - 0.1% = 99.9%.

Therefore, the correct answer is:
- **99.9%**
Transcribed Image Text:### Understanding Normal Distribution and Heights of College Women **Problem Statement:** Assuming that the heights of college women are normally distributed with a mean of 67 inches and a standard deviation of 2 inches, what percentage of women are taller than 61 inches? **Possible Answers:** - 97.7% - 99.9% - 15.9% - 50.0% - 0.1% **Explanation:** To solve this problem, we need to use the properties of the normal distribution. According to the empirical rule (also known as the 68-95-99.7 rule), for a normal distribution: 1. About 68% of values fall within one standard deviation of the mean. 2. About 95% of values fall within two standard deviations of the mean. 3. About 99.7% of values fall within three standard deviations of the mean. The z-score formula for a given value \(X\) in a normal distribution is: \[ Z = \frac{X - \mu}{\sigma} \] Where: - \( \mu \) is the mean - \( \sigma \) is the standard deviation - \( X \) is the value for which we are calculating the z-score For \(X = 61\): \[ Z = \frac{61 - 67}{2} = \frac{-6}{2} = -3 \] A z-score of -3 means that 61 inches is 3 standard deviations below the mean. Looking at standard normal distribution tables, a z-score of -3 corresponds to a percentile of about 0.1%, meaning 0.1% of the women are shorter than 61 inches. Therefore, the percentage of women taller than 61 inches is approximately 100% - 0.1% = 99.9%. Therefore, the correct answer is: - **99.9%**
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps with 4 images

Blurred answer
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