BASIC PRACTICE OF STATISTICS+LAUNCHPAD
BASIC PRACTICE OF STATISTICS+LAUNCHPAD
8th Edition
ISBN: 9781319053093
Author: Moore
Publisher: MAC HIGHER
bartleby

Videos

Question
Book Icon
Chapter 17, Problem 17.38E

(a)

To determine

To test: Whether there is any statistically significant evidence at the α=0.10 level against the hypothesis that the mean is 32,500 pounds or not for the two-sided alternative.

(a)

Expert Solution
Check Mark

Answer to Problem 17.38E

There is statistically significant difference at α=0.10 level against the hypothesis that the mean is 32,500 pounds.

Explanation of Solution

Given info:

The data represents the sample of strength of pieces of wood and standard deviation 3,000 pounds.

Calculation:

STATE:

The strength of pieces of wood follows normal distribution with standard deviation σ=3,000. Moreover, a sample of 20 pieces is selected from the population. Is there statistically significant evidence at the α=0.10 level against the hypothesis that the mean is 32,500 pounds for the two-sided alternative?

PLAN:

Parameter:

Define the parameter μ as the mean strength of pieces of wood.

The hypotheses are given below:

The claim of the problem is the mean strength is different from 32,500.

Null Hypothesis:

H0:μ=32,500

That is, the mean strength is equal to 32,500.

Alternative hypothesis:

Ha:μ32,500

That is, the mean strength is not equal to 32,500.

SOLVE:

Conditions for valid test:

A sample of 20 pieces of wood is randomly selected and strength of pieces of wood follows normal distribution with standard deviation σ=3,000.

Test statistic and P-value:

Software procedure:

Step-by-step procedure to obtain test statistic and P-value using the MINITAB software:

  • Choose Stat > Basic Statistics > 1-Sample Z.
  • In Samples in Column, enter the column of Strength of pieces.
  • In Standard deviation, enter 3,000.
  • In Perform hypothesis test, enter the test mean as 32,500.
  • Check Options, enter Confidence level as 90.
  • Choose not equal in alternative.
  • Click OK in all dialogue boxes.

Output using the MINITAB software is given below:

BASIC PRACTICE OF STATISTICS+LAUNCHPAD, Chapter 17, Problem 17.38E , additional homework tip  1

From the MINITAB output, the test statistic is –2.47 and the P-value is 0.013.

Decision criteria for the P-value method:

If P-valueα(=0.10), then reject the null hypothesis (H0).

If P-value>α(=0.10), then fail to reject the null hypothesis (H0).

CONCLUDE:

Use a significance level, α=0.10.

Here, P-value is 0.013, which is lesser than the value of α=0.10.

That is, P-value(=0.013)<α(=0.10).

Therefore, the null hypothesis is rejected.

Thus, there is statistically significant at α=0.10 level against the hypothesis that the mean is 32,500 pounds.

(b)

To determine

To test: Whether there is any statistically significant evidence at the α=0.10 level against the hypothesis that the mean is 31,500 pounds or not for the two-sided alternative.

(b)

Expert Solution
Check Mark

Answer to Problem 17.38E

There is no statistically significant difference at α=0.10 level against the hypothesis that the mean is 31,500 pounds.

Explanation of Solution

Calculation:

STATE:

Is there statistically significant evidence at the α=0.10 level against the hypothesis that the mean is 31,500 pounds for the two-sided alternative?

PLAN:

Parameter:

Define the parameter μ as the mean strength of pieces of wood.

The hypotheses are given below:

The claim of the problem is the mean strength is different from 31,500.

Null Hypothesis:

H0:μ=31,500

That is, the mean strength is equal to 31,500.

Alternative hypothesis:

Ha:μ31,500

That is, the mean strength is not equal to 31,500.

SOLVE:

Conditions for valid test:

A sample of 20 pieces of wood is randomly selected and strength of pieces of wood follows normal distribution with standard deviation σ=3,000.

Test statistic and P-value:

Software procedure:

Step-by-step procedure to obtain test statistic and P-value using the MINITAB software:

  • Choose Stat > Basic Statistics > 1-Sample Z.
  • In Samples in Column, enter the column of Strength of pieces.
  • In Standard deviation, enter 3,000.
  • In Perform hypothesis test, enter the test mean as 31,500.
  • Check Options, enter Confidence level as 90.
  • Choose not equal in alternative.
  • Click OK in all dialogue boxes.

Output using the MINITAB software is given below:

BASIC PRACTICE OF STATISTICS+LAUNCHPAD, Chapter 17, Problem 17.38E , additional homework tip  2

From the MINITAB output, the test statistic is –0.98 and the P-value is 0.326.

CONCLUDE:

Use a significance level, α=0.10.

Here, P-value is 0.326, which is greater than the value of α=0.10.

That is, P-value(=0.326)>α(=0.10).

Therefore, the null hypothesis is not rejected.

Thus, there is no statistically significant difference at α=0.10 level against the hypothesis that the mean is 31,500 pounds.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
Could you please answer this question using excel. For 1a) I got 84.75 and for part 1b) I got 85.33 and was wondering if you could check if my answers were correct. Thanks
What is one sample T-test? Give an example of business application of this test? What is Two-Sample T-Test. Give an example of business application of this test? .What is paired T-test. Give an example of business application of this test? What is one way ANOVA test. Give an example of business application of this test? 1. One Sample T-Test: Determine whether the average satisfaction rating of customers for a product is significantly different from a hypothetical mean of 75.  (Hints: The null can be about maintaining status-quo or no difference; If your alternative hypothesis is non-directional (e.g., μ≠75), you should use the two-tailed p-value from excel file to make a decision about rejecting or not rejecting null. If alternative is directional (e.g., μ < 75), you should use the lower-tailed p-value. For alternative hypothesis μ > 75, you should use the upper-tailed p-value.)   H0 =   H1=   Conclusion: The p value from one sample t-test is _______. Since the two-tailed p-value…
Using the accompanying Accounting Professionals data to answer the following questions.   a. Find and interpret a 90​% confidence interval for the mean years of service. b. Find and interpret a 90​% confidence interval for the proportion of employees who have a graduate degree.    view the Accounting Professionals data. Employee    Years of Service    Graduate Degree?1    26    Y2    8    N3    10    N4    6    N5    23    N6    5    N7    8    Y8    5    N9    26    N10    14    Y11    10    N12    8    Y13    7    Y14    27    N15    16    Y16    17    N17    21    N18    9    Y19    9    N20    9    N     Question content area bottom Part 1 a. A 90​% confidence interval for the mean years of service is   ​(Use ascending order. Round to two decimal places as​ needed.)
Knowledge Booster
Background pattern image
Statistics
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
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
MATLAB: An Introduction with Applications
Statistics
ISBN:9781119256830
Author:Amos Gilat
Publisher:John Wiley & Sons Inc
Text book image
Probability and Statistics for Engineering and th...
Statistics
ISBN:9781305251809
Author:Jay L. Devore
Publisher:Cengage Learning
Text book image
Statistics for The Behavioral Sciences (MindTap C...
Statistics
ISBN:9781305504912
Author:Frederick J Gravetter, Larry B. Wallnau
Publisher:Cengage Learning
Text book image
Elementary Statistics: Picturing the World (7th E...
Statistics
ISBN:9780134683416
Author:Ron Larson, Betsy Farber
Publisher:PEARSON
Text book image
The Basic Practice of Statistics
Statistics
ISBN:9781319042578
Author:David S. Moore, William I. Notz, Michael A. Fligner
Publisher:W. H. Freeman
Text book image
Introduction to the Practice of Statistics
Statistics
ISBN:9781319013387
Author:David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:W. H. Freeman
Introduction to experimental design and analysis of variance (ANOVA); Author: Dr. Bharatendra Rai;https://www.youtube.com/watch?v=vSFo1MwLoxU;License: Standard YouTube License, CC-BY