La Leche League International reports that the mean age of weaning a child from breastfeeding is age four to five worldwide. In America, most nursing mothers wean their children much earlier. Suppose a random survey is conducted of 21 U.S. mothers who recently weaned their children. The mean weaning age was 9 months (3/4 year) with a standard deviation of 2 months. Conduct a hypothesis test to determine if the mean weaning age in the U.S. is less than four years old. Conduct a hypothesis test at the 5% level. Note: If you are using a Student's t-distribution for the problem, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.) Part (a)         Part (b)         Part (c)           Part (d) State the distribution to use for the test. (Enter your answer in the form z or tdf where df is the degrees of freedom.)       Part (e) What is the test statistic? (If using the z distribution round your answers to two decimal places, and if using the t distribution round your answers to three decimal places.)      =  Part (f) What is the p-value? (Round your answer to four decimal places.) Explain what the p-value means for this problem. If H0 is true, then there is a chance equal to the p-value that the average age at which American mothers wean their children is equal to the sample mean or less.If H0 is true, then there is a chance equal to the p-value that the average age at which American mothers wean their children is equal to the sample mean or more.    If H0 is false, then there is a chance equal to the p-value that the average age at which American mothers wean their children is equal to the sample mean or more.If H0 is false, then there is a chance equal to the p-value that the average age at which American mothers wean their children is equal to the sample mean or less. Correct! A p-value is the probability that an outcome of the data will happen purely by chance when  H0  is true. Part (g)         Part (h) Indicate the correct decision ("reject" or "do not reject" the null hypothesis), the reason for it, and write an appropriate conclusion. (i) Alpha (Enter an exact number as an integer, fraction, or decimal.) ? =  (ii) Decision: reject the null hypothesisdo not reject the null hypothesis     (iii) Reason for decision: Since ? < p-value, we do not reject the null hypothesis.Since ? < p-value, we reject the null hypothesis.    Since ? > p-value, we do not reject the null hypothesis.Since ? > p-value, we reject the null hypothesis. (iv) Conclusion: There is sufficient evidence to conclude that mean age at which American mothers wean their children is less than 4.There is not sufficient evidence to conclude that mean age at which American mothers wean their children is less than 4.     Part (i) Construct a 95% confidence interval for the true mean. Sketch the graph of the situation. Label the point estimate and the lower and upper bounds of the confidence interval. (Enter your answers in years. Round your answers to four decimal places.)

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
La Leche League International reports that the mean age of weaning a child from breastfeeding is age four to five worldwide. In America, most nursing mothers wean their children much earlier. Suppose a random survey is conducted of 21 U.S. mothers who recently weaned their children. The mean weaning age was 9 months (3/4 year) with a standard deviation of 2 months. Conduct a hypothesis test to determine if the mean weaning age in the U.S. is less than four years old. Conduct a hypothesis test at the 5% level.

Note: If you are using a Student's t-distribution for the problem, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.)

  • Part (a)

     
     
     
     
  • Part (b)

     
     
     
     
  • Part (c)

     
     
     
     
     
  • Part (d)

    State the distribution to use for the test. (Enter your answer in the form z or tdf where df is the degrees of freedom.)
     
     
     
  • Part (e)

    What is the test statistic? (If using the z distribution round your answers to two decimal places, and if using the t distribution round your answers to three decimal places.)
         = 
  • Part (f)

    What is the p-value? (Round your answer to four decimal places.)


    Explain what the p-value means for this problem.
    If H0 is true, then there is a chance equal to the p-value that the average age at which American mothers wean their children is equal to the sample mean or less.If H0 is true, then there is a chance equal to the p-value that the average age at which American mothers wean their children is equal to the sample mean or more.    If H0 is false, then there is a chance equal to the p-value that the average age at which American mothers wean their children is equal to the sample mean or more.If H0 is false, then there is a chance equal to the p-value that the average age at which American mothers wean their children is equal to the sample mean or less.
    Correct! A p-value is the probability that an outcome of the data will happen purely by chance when 
    H0
     is true.
  • Part (g)

       
       
  • Part (h)

    Indicate the correct decision ("reject" or "do not reject" the null hypothesis), the reason for it, and write an appropriate conclusion.
    (i) Alpha (Enter an exact number as an integer, fraction, or decimal.)
    ? = 

    (ii) Decision:
    reject the null hypothesisdo not reject the null hypothesis    

    (iii) Reason for decision:
    Since ? < p-value, we do not reject the null hypothesis.Since ? < p-value, we reject the null hypothesis.    Since ? > p-value, we do not reject the null hypothesis.Since ? > p-value, we reject the null hypothesis.

    (iv) Conclusion:
    There is sufficient evidence to conclude that mean age at which American mothers wean their children is less than 4.There is not sufficient evidence to conclude that mean age at which American mothers wean their children is less than 4.    
  • Part (i)

    Construct a 95% confidence interval for the true mean. Sketch the graph of the situation. Label the point estimate and the lower and upper bounds of the confidence interval. (Enter your answers in years. Round your answers to four decimal places.)
     
 

Additional Materials

  • eBook
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 4 steps

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.
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