Suppose that grade point averages of undergraduate students at one university have a bell- shaped distribution with a mean of 2.59 and a standard deviation of 0.39. Using the empirical rule, what percentage of the students have grade point averages that are between 1.42 and 3.76?

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
**Question 20:**

Suppose that grade point averages of undergraduate students at one university have a bell-shaped distribution with a mean of 2.59 and a standard deviation of 0.39. Using the empirical rule, what percentage of the students have grade point averages that are between 1.42 and 3.76? 

**Explanation for Educational Website:**

To solve this problem, we apply the empirical rule (also known as the 68-95-99.7 rule) which states that for a normal distribution:

- About 68% of the data falls within one standard deviation from the mean.
- About 95% of the data falls within two standard deviations from the mean.
- About 99.7% of the data falls within three standard deviations from the mean.

Here, we calculate how many standard deviations 1.42 and 3.76 are from the mean of 2.59:

1. **Calculate the number of standard deviations for 1.42:**  
   - \( \text{Lower bound} = \frac{2.59 - 1.42}{0.39} = 3 \) standard deviations below the mean.

2. **Calculate the number of standard deviations for 3.76:**  
   - \( \text{Upper bound} = \frac{3.76 - 2.59}{0.39} = 3 \) standard deviations above the mean.

Since 1.42 and 3.76 are each 3 standard deviations away from the mean, according to the empirical rule, approximately 99.7% of the students have GPAs in this range.
Transcribed Image Text:**Question 20:** Suppose that grade point averages of undergraduate students at one university have a bell-shaped distribution with a mean of 2.59 and a standard deviation of 0.39. Using the empirical rule, what percentage of the students have grade point averages that are between 1.42 and 3.76? **Explanation for Educational Website:** To solve this problem, we apply the empirical rule (also known as the 68-95-99.7 rule) which states that for a normal distribution: - About 68% of the data falls within one standard deviation from the mean. - About 95% of the data falls within two standard deviations from the mean. - About 99.7% of the data falls within three standard deviations from the mean. Here, we calculate how many standard deviations 1.42 and 3.76 are from the mean of 2.59: 1. **Calculate the number of standard deviations for 1.42:** - \( \text{Lower bound} = \frac{2.59 - 1.42}{0.39} = 3 \) standard deviations below the mean. 2. **Calculate the number of standard deviations for 3.76:** - \( \text{Upper bound} = \frac{3.76 - 2.59}{0.39} = 3 \) standard deviations above the mean. Since 1.42 and 3.76 are each 3 standard deviations away from the mean, according to the empirical rule, approximately 99.7% of the students have GPAs in this range.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 1 images

Blurred answer
Knowledge Booster
Point Estimation, Limit Theorems, Approximations, and Bounds
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE 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