From a population with a variance of 1296, a sample of 225 items is selected. At 95% confidence, the margin of error is O 0.31 169.34 4.70 1.96 Clear my choice

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
**Confidence Interval and Margin of Error**

When working with statistical data, one of the essential concepts to understand is the margin of error when estimating population parameters based on sample data. This helps in determining how precise our estimate is and gives us a range in which we expect the true population parameter to lie.

In this example, we will explore how to calculate the margin of error at a 95% confidence level given specific parameters. 

**Problem Statement:**

From a population with a variance of 1296, a sample of 225 items is selected. At 95% confidence, the margin of error is to be determined. 

There are four answer options provided:
- 0.31
- 169.34
- 4.70 (this option is selected)
- 1.96

**Understanding the Options:**

To calculate the margin of error (E), we use the following formula:

\[ E = z \times \frac{\sigma}{\sqrt{n}} \]

where
- \( z \) is the z-score corresponding to the desired confidence level (For a 95% confidence level, the z-score is approximately 1.96)
- \( \sigma \) is the population standard deviation
- \( n \) is the sample size

Given:
- Population variance (\( \sigma^2 \)) = 1296
- Sample size (\( n \)) = 225

First, we need to find the population standard deviation (\( \sigma \)):

\[ \sigma = \sqrt{1296} = 36 \]

Next, substitute the values into the formula:

\[ E = 1.96 \times \frac{36}{\sqrt{225}} \]

Calculate the denominator:

\[ \sqrt{225} = 15 \]

Therefore:

\[ E = 1.96 \times \frac{36}{15} = 1.96 \times 2.4 = 4.704 \]

Thus, the margin of error, rounded to two decimal places, is approximately 4.70.

**Conclusion:**

The margin of error at a 95% confidence level for a sample of 225 items from a population with a variance of 1296 is 4.70. Thus, the correct answer in the given options is 4.70.
Transcribed Image Text:**Confidence Interval and Margin of Error** When working with statistical data, one of the essential concepts to understand is the margin of error when estimating population parameters based on sample data. This helps in determining how precise our estimate is and gives us a range in which we expect the true population parameter to lie. In this example, we will explore how to calculate the margin of error at a 95% confidence level given specific parameters. **Problem Statement:** From a population with a variance of 1296, a sample of 225 items is selected. At 95% confidence, the margin of error is to be determined. There are four answer options provided: - 0.31 - 169.34 - 4.70 (this option is selected) - 1.96 **Understanding the Options:** To calculate the margin of error (E), we use the following formula: \[ E = z \times \frac{\sigma}{\sqrt{n}} \] where - \( z \) is the z-score corresponding to the desired confidence level (For a 95% confidence level, the z-score is approximately 1.96) - \( \sigma \) is the population standard deviation - \( n \) is the sample size Given: - Population variance (\( \sigma^2 \)) = 1296 - Sample size (\( n \)) = 225 First, we need to find the population standard deviation (\( \sigma \)): \[ \sigma = \sqrt{1296} = 36 \] Next, substitute the values into the formula: \[ E = 1.96 \times \frac{36}{\sqrt{225}} \] Calculate the denominator: \[ \sqrt{225} = 15 \] Therefore: \[ E = 1.96 \times \frac{36}{15} = 1.96 \times 2.4 = 4.704 \] Thus, the margin of error, rounded to two decimal places, is approximately 4.70. **Conclusion:** The margin of error at a 95% confidence level for a sample of 225 items from a population with a variance of 1296 is 4.70. Thus, the correct answer in the given options is 4.70.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps

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