(a) Compute a 95% confidence interval for u, - Hz. (Use 2 decimal places.) lower limit upper limit (b) Comment on the meaning of the confidence interval in the context of this problem. Does the interval consist of positive numbers only? negative numbers only? a mix of positive and negative numbers? Does it appear (at the 95% confidence level) that a change in the interval length between eruptions has occurred? Many geologic experts believe that the distribution of eruption times of Old Faithful changed after the major earthquake that occurred in 1959. O Recauce the inten/al contains oply nocitive puumbers we can cay that the in on/al lonath between oru.n cotten chortor

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
The U.S. Geological Survey compiled historical data about Old Faithful Geyser (Yellowstone National Park) from 1870 to 1987. Let \( x_1 \) be a random variable that represents the time interval (in minutes) between Old Faithful eruptions for the years 1948 to 1952. Based on 8800 observations, the sample mean interval was \( \bar{x}_1 = 64.0 \) minutes. Let \( x_2 \) be a random variable that represents the time interval in minutes between Old Faithful eruptions for the years 1983 to 1987. Based on 23,936 observations, the sample mean time interval was \( \bar{x}_2 = 72.4 \) minutes. Historical data suggest that \( \sigma_1 = 8.35 \) minutes and \( \sigma_2 = 12.69 \) minutes. Let \( \mu_1 \) be the population mean of \( x_1 \) and let \( \mu_2 \) be the population mean of \( x_2 \).

(a) Compute a 95% confidence interval for \( \mu_1 - \mu_2 \). (Use 2 decimal places.)

- lower limit: [ ]
- upper limit: [ ]

(b) Comment on the meaning of the confidence interval in the context of this problem. Does the interval consist of positive numbers only? negative numbers only? a mix of positive and negative numbers? Does it appear (at the 95% confidence level) that a change in the interval length between eruptions has occurred? Many geologic experts believe that the distribution of eruption times of Old Faithful changed after the major earthquake that occurred in 1959.

- Because the interval contains only positive numbers, we can say that the interval length between eruptions has gotten shorter.
  
- Because the interval contains both positive and negative numbers, we can not say that the interval length between eruptions has gotten longer.
  
- We can not make any conclusions using this confidence interval.
  
- Because the interval contains only negative numbers, we can say that the interval length between eruptions has gotten longer.
Transcribed Image Text:The U.S. Geological Survey compiled historical data about Old Faithful Geyser (Yellowstone National Park) from 1870 to 1987. Let \( x_1 \) be a random variable that represents the time interval (in minutes) between Old Faithful eruptions for the years 1948 to 1952. Based on 8800 observations, the sample mean interval was \( \bar{x}_1 = 64.0 \) minutes. Let \( x_2 \) be a random variable that represents the time interval in minutes between Old Faithful eruptions for the years 1983 to 1987. Based on 23,936 observations, the sample mean time interval was \( \bar{x}_2 = 72.4 \) minutes. Historical data suggest that \( \sigma_1 = 8.35 \) minutes and \( \sigma_2 = 12.69 \) minutes. Let \( \mu_1 \) be the population mean of \( x_1 \) and let \( \mu_2 \) be the population mean of \( x_2 \). (a) Compute a 95% confidence interval for \( \mu_1 - \mu_2 \). (Use 2 decimal places.) - lower limit: [ ] - upper limit: [ ] (b) Comment on the meaning of the confidence interval in the context of this problem. Does the interval consist of positive numbers only? negative numbers only? a mix of positive and negative numbers? Does it appear (at the 95% confidence level) that a change in the interval length between eruptions has occurred? Many geologic experts believe that the distribution of eruption times of Old Faithful changed after the major earthquake that occurred in 1959. - Because the interval contains only positive numbers, we can say that the interval length between eruptions has gotten shorter. - Because the interval contains both positive and negative numbers, we can not say that the interval length between eruptions has gotten longer. - We can not make any conclusions using this confidence interval. - Because the interval contains only negative numbers, we can say that the interval length between eruptions has gotten longer.
Expert Solution
steps

Step by step

Solved in 2 steps with 1 images

Blurred answer
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