IDNLearn.com offers a collaborative platform for sharing and gaining knowledge. Our platform provides detailed and accurate responses from experts, helping you navigate any topic with confidence.
Sagot :
To calculate the 90% confidence interval for the mean airborne time for flights from San Francisco to Washington Dulles based on the provided data set of airborne times, we will follow several steps:
1. List the Data: The given airborne times (in minutes) for 10 flights are:
270, 256, 267, 286, 274, 275, 266, 258, 271, 281.
2. Calculate the Sample Mean ([tex]\( \bar{X} \)[/tex]):
[tex]\[ \bar{X} = \frac{270 + 256 + 267 + 286 + 274 + 275 + 266 + 258 + 271 + 281}{10} = 270.4 \text{ minutes} \][/tex]
3. Calculate the Sample Standard Deviation (s):
[tex]\[ s = 9.324 \text{ minutes} \quad \text{(to three decimal places)} \][/tex]
4. Determine the Sample Size (n):
[tex]\[ n = 10 \][/tex]
5. Calculate the Standard Error of the Mean ([tex]\( SE \)[/tex]):
[tex]\[ SE = \frac{s}{\sqrt{n}} = \frac{9.324}{\sqrt{10}} = 2.948 \text{ minutes} \quad \text{(to three decimal places)} \][/tex]
6. Determine the t-multiplier for a 90% Confidence Level:
For a 90% confidence level and degrees of freedom [tex]\( df = n - 1 = 9 \)[/tex]:
[tex]\[ t_{\alpha/2} = 1.833 \quad \text{(from t-distribution table)} \][/tex]
7. Calculate the Margin of Error (ME):
[tex]\[ ME = t_{\alpha/2} \times SE = 1.833 \times 2.948 = 5.405 \text{ minutes} \quad \text{(to three decimal places)} \][/tex]
8. Compute the Confidence Interval:
[tex]\[ \text{Lower Bound} = \bar{X} - ME = 270.4 - 5.405 = 264.995 \text{ minutes} \quad \text{(to three decimal places)} \][/tex]
[tex]\[ \text{Upper Bound} = \bar{X} + ME = 270.4 + 5.405 = 275.805 \text{ minutes} \quad \text{(to three decimal places)} \][/tex]
So, the 90% confidence interval for the mean airborne time for flights from San Francisco to Washington Dulles is:
[tex]\[ \boxed{264.995} \quad \text{to} \quad \boxed{275.805} \][/tex]
Interpretation of the 90% Confidence Interval:
We are 90% confident that the mean airborne time for flights from San Francisco to Washington Dulles is between these two values.
1. List the Data: The given airborne times (in minutes) for 10 flights are:
270, 256, 267, 286, 274, 275, 266, 258, 271, 281.
2. Calculate the Sample Mean ([tex]\( \bar{X} \)[/tex]):
[tex]\[ \bar{X} = \frac{270 + 256 + 267 + 286 + 274 + 275 + 266 + 258 + 271 + 281}{10} = 270.4 \text{ minutes} \][/tex]
3. Calculate the Sample Standard Deviation (s):
[tex]\[ s = 9.324 \text{ minutes} \quad \text{(to three decimal places)} \][/tex]
4. Determine the Sample Size (n):
[tex]\[ n = 10 \][/tex]
5. Calculate the Standard Error of the Mean ([tex]\( SE \)[/tex]):
[tex]\[ SE = \frac{s}{\sqrt{n}} = \frac{9.324}{\sqrt{10}} = 2.948 \text{ minutes} \quad \text{(to three decimal places)} \][/tex]
6. Determine the t-multiplier for a 90% Confidence Level:
For a 90% confidence level and degrees of freedom [tex]\( df = n - 1 = 9 \)[/tex]:
[tex]\[ t_{\alpha/2} = 1.833 \quad \text{(from t-distribution table)} \][/tex]
7. Calculate the Margin of Error (ME):
[tex]\[ ME = t_{\alpha/2} \times SE = 1.833 \times 2.948 = 5.405 \text{ minutes} \quad \text{(to three decimal places)} \][/tex]
8. Compute the Confidence Interval:
[tex]\[ \text{Lower Bound} = \bar{X} - ME = 270.4 - 5.405 = 264.995 \text{ minutes} \quad \text{(to three decimal places)} \][/tex]
[tex]\[ \text{Upper Bound} = \bar{X} + ME = 270.4 + 5.405 = 275.805 \text{ minutes} \quad \text{(to three decimal places)} \][/tex]
So, the 90% confidence interval for the mean airborne time for flights from San Francisco to Washington Dulles is:
[tex]\[ \boxed{264.995} \quad \text{to} \quad \boxed{275.805} \][/tex]
Interpretation of the 90% Confidence Interval:
We are 90% confident that the mean airborne time for flights from San Francisco to Washington Dulles is between these two values.
Thank you for participating in our discussion. We value every contribution. Keep sharing knowledge and helping others find the answers they need. Let's create a dynamic and informative learning environment together. Your questions deserve reliable answers. Thanks for visiting IDNLearn.com, and see you again soon for more helpful information.