A random sample of n1 = 10 regions in New England gave the following violent crime rates (per million population). x1:   New England Crime Rate 3.8 3.9 5.0 3.4 3.3 4.1 1.8 4.8 2.9 3.1 Another random sample of n2 = 12 regions in the Rocky Mountain states gave the following violent crime rates (per million population). x2:   Rocky Mountain Crime Rate 3.5 4.2 4.6 5.0 3.3 4.8 3.5 2.4 3.1 3.5 5.2 2.8 Assume that the crime rate distribution is approximately normal in both regions. Note: If a two-sample t-test is appropriate, for degrees of freedom d.f. not in the Student's t table, use the closest d.f. that is smaller. In some situations, this choice of d.f. may increase the P-value by a small amount and therefore produce a slightly more "conservative" answer.Use a calculator to calculate  x1 , s1,  x2 , and s2. (Round your answers to two decimal places.) x1 =   s1 =   x2 =   s2 =     (a) Do the data indicate that the violent crime rate in the Rocky Mountain region is higher than in New England? Use α = 0.01. (i) What is the level of significance?State the null and alternate hypotheses. H0: μ1 = μ2; H1: μ1 > μ2H0: μ1 < μ2; H1: μ1 = μ2     H0: μ1 = μ2; H1: μ1 < μ2H0: μ1 = μ2; H1: μ1 ≠ μ2H0: μ1 ≠ μ2; H1: μ1 = μ2 (ii) What sampling distribution will you use? What assumptions are you making? The standard normal. We assume that both population distributions are approximately normal with known standard deviations.The Student's t. We assume that both population distributions are approximately normal with known standard deviations.     The Student's t. We assume that both population distributions are approximately normal with unknown standard deviations.The standard normal. We assume that both population distributions are approximately normal with unknown standard deviations. What is the value of the sample test statistic? (Test the difference μ1 − μ2. Round your answer to three decimal places.)(iii) Find the P-value. (Round your answer to four decimal places.)Sketch the sampling distribution and show the area corresponding to the P-value.         (iv) Based on your answers in parts (i) to (iii), will you reject or fail to reject the null hypothesis? Are the data statistically significant at level α? Since the P-value ≤ α, we reject H0. The data are statistically significant.Since the P-value > α, we reject H0. The data are not statistically significant.     Since the P-value > α, we fail to reject H0. The data are not statistically significant.Since the P-value ≤ α, we fail to reject H0. The data are statistically significant. (v) Interpret your conclusion in the context of the application. Reject H0. At the 1% level of significance, the evidence is insufficient to indicate that violent crime in the Rocky Mountain region is higher than in New England.Fail to reject H0. At the 1% level of significance, the evidence is insufficient to indicate that violent crime in the Rocky Mountain region is higher than in New England.     Fail to reject H0. At the 1% level of significance, the evidence is sufficient to indicate that violent crime in the Rocky Mountain region is higher than in New England.Reject H0. At the 1% level of significance, the evidence is sufficient to indicate that violent crime in the Rocky Mountain region is higher than in New England. (b) Find a 98% confidence interval for μ1 − μ2. (Round your answers to two decimal places.) lower limit        upper limit        Explain the meaning of the confidence interval in the context of the problem. At the 98% level of confidence, we can conclude that the population mean violence rates are different.At the 98% level of confidence, we cannot conclude that the population mean violence rates are different.

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
Topic Video
Question

A random sample of n1 = 10 regions in New England gave the following violent crime rates (per million population).

x1:   New England Crime Rate
3.8 3.9 5.0 3.4 3.3 4.1 1.8 4.8 2.9 3.1

Another random sample of n2 = 12 regions in the Rocky Mountain states gave the following violent crime rates (per million population).

x2:   Rocky Mountain Crime Rate
3.5 4.2 4.6 5.0 3.3 4.8 3.5 2.4 3.1 3.5 5.2 2.8

Assume that the crime rate distribution is approximately normal in both regions. Note: If a two-sample t-test is appropriate, for degrees of freedom d.f. not in the Student's t table, use the closest d.f. that is smaller. In some situations, this choice of d.f. may increase the P-value by a small amount and therefore produce a slightly more "conservative" answer.

Use a calculator to calculate 

x1

s1

x2

, and s2. (Round your answers to two decimal places.)

x1
=  
s1
=  
x2
=  
s2
=  

 

(a) Do the data indicate that the violent crime rate in the Rocky Mountain region is higher than in New England? Use α = 0.01.
(i) What is the level of significance?


State the null and alternate hypotheses.
H0: μ1 = μ2; H1: μ1 > μ2H0: μ1 < μ2; H1: μ1 = μ2     H0: μ1 = μ2; H1: μ1 < μ2H0: μ1 = μ2; H1: μ1 ≠ μ2H0: μ1 ≠ μ2; H1: μ1 = μ2

(ii) What sampling distribution will you use? What assumptions are you making?
The standard normal. We assume that both population distributions are approximately normal with known standard deviations.The Student's t. We assume that both population distributions are approximately normal with known standard deviations.     The Student's t. We assume that both population distributions are approximately normal with unknown standard deviations.The standard normal. We assume that both population distributions are approximately normal with unknown standard deviations.

What is the value of the sample test statistic? (Test the difference μ1 − μ2. Round your answer to three decimal places.)


(iii) Find the P-value. (Round your answer to four decimal places.)


Sketch the sampling distribution and show the area corresponding to the P-value.
   
   

(iv) Based on your answers in parts (i) to (iii), will you reject or fail to reject the null hypothesis? Are the data statistically significant at level α?
Since the P-value ≤ α, we reject H0. The data are statistically significant.Since the P-value > α, we reject H0. The data are not statistically significant.     Since the P-value > α, we fail to reject H0. The data are not statistically significant.Since the P-value ≤ α, we fail to reject H0. The data are statistically significant.

(v) Interpret your conclusion in the context of the application.
Reject H0. At the 1% level of significance, the evidence is insufficient to indicate that violent crime in the Rocky Mountain region is higher than in New England.Fail to reject H0. At the 1% level of significance, the evidence is insufficient to indicate that violent crime in the Rocky Mountain region is higher than in New England.     Fail to reject H0. At the 1% level of significance, the evidence is sufficient to indicate that violent crime in the Rocky Mountain region is higher than in New England.Reject H0. At the 1% level of significance, the evidence is sufficient to indicate that violent crime in the Rocky Mountain region is higher than in New England.
(b) Find a 98% confidence interval for μ1 − μ2. (Round your answers to two decimal places.)
lower limit       
upper limit       

Explain the meaning of the confidence interval in the context of the problem.
At the 98% level of confidence, we can conclude that the population mean violence rates are different.At the 98% level of confidence, we cannot conclude that the population mean violence rates are different.    

 

Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps with 5 images

Blurred answer
Knowledge Booster
Hypothesis Tests and Confidence Intervals for Proportions
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
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