Skip to main content

The compressive strength (Y) of concrete is...

Just Click on Below Link To Download This Course:

https://bit.ly/2LodG9D

MIS 660 Topic 8 Multiple Regression Analysis GCU

The purpose of this assignment is to apply multiple regression concepts, interpret multiple regression analysis models, and justify business predictions based upon the analysis.

For this assignment, you will use the “Strength” dataset. You will use SPSS to analyze the dataset and address the questions presented. Findings should be presented in a Word document along with the SPSS outputs.

The compressive strength (Y) of concrete is influenced by the mixing proportions and by the time that it is allowed to cure, although the exact relationship between the strength and the components is unknown. The provided data includes the results of n = 1030 concrete strength experiments that include the following:

  1. Strength (in MPa): The compressive strength of the concrete.
  2. Age (in days): The number of days the concrete was allowed to cured.
  3. Coarse_Aggregate (in kg/m3): The proportion of coarse aggregate in the mix.
  4. Fine_Aggregate (in kg/m3): The proportion of fine aggregate in the mix.
  5. Cement (in kg/m3): The proportion of cement in the mix.
  6. Slag (in kg/m3): The proportion of furnace slag in the mix.
  7. Superplasticizer (in kg/m3): The proportion of plasticizer in the mix.
  8. Water (in kg/m3): The proportion of water in the mix.
  9. Ash (in kg/m3): The proportion of fly ash in the mix.

Part 1:

Derive various transformations of compressive strength to determine which transformation, if any, results in a variable that most closely mimics a normal distribution. To do this, plot Q-Q plots after each transformation listed below, and decide which one should be used to build a multiple linear model. Explain your answer and provide the SPSS output as an illustration.

  1. Strength (no transformation)
  2. Square root of Strength
  3. Squared Strength
  4. (Natural) Log of Strength
  5. Reciprocal of Strength

Part 2:

Based on the transformation selected in Part 1, build a multiple linear regression model with all eight predictors.

  1. Use t-tests to determine if any of the predictors significantly affect the compressive strength of concrete. Explain why each variable should or should not be included in the model. Assume α = 0.05. Show the appropriate model results to explain your answer.
  2. If any predictors from question 1 are found to be not significant, remove them and re-run the model to create a reduced model (RM). Are all the remaining variables still statistically significant? Show the appropriate model results to explain your answer.
  3. Based on the RM, should there be concern about multicollinearity among the predictors selected? Show the appropriate model results to explain your answer.
  4. After fitting the RM, derive the residual plot (standardized residuals vs. standardized predicted values) and normal probability plot. Interpret each plot.
  5. What is the coefficient of determination, R2, of the RM? How would you interpret the R2?
  6. Based on the RM, what would be the new estimated compressive strength that is currently 50 MPa, after a 10-day increase in curing time? Assume all other predictors are held constant.
  7. How would you interpret the intercept (constant) in the RM? Does the interpretation make sense given the data you used to build the RM?

Part 3:

Given the following components and aging time below, what is the estimated compressive strength based on the RM?

  1. Age: 50 days
  2. Coarse_Aggregate: 900 kg/m3
  3. Fine_Aggregate: 600 kg/m3
  4. Cement: 300 kg/m3
  5. Slag: 200 kg/m3
  6. Superplasticizer: 7 kg/m3
  7. Water: 190 kg/m3
  8. Ash: 70 kg/m3

Part 4:

What is a 95% confidence interval of the estimate in Part 3? How would you interpret the 95% confidence interval? (Hint: Use the SPSS scoring wizard to address this question.)

APA format is not required, but solid academic writing is expected.

This assignment uses a grading rubric. Please review the rubric prior to beginning the assignment to become familiar with the expectations for successful completion.

You are not required to submit this assignment to LopesWrite.

 

Download Now

 

 

Labels:

Comments

Post a Comment

Popular posts from this blog

SPD 320 All Discussions GCU

Just Click on Below Link To Download This Course: https://mindsblow.com/product/spd-320-discussions-gcu/ SPD 320 All Discussions GCU SPD 320 Topic 1 DQ 1 Which of IDEA’s eligibility categories do you feel is most difficult to assess via mandated eligibility assessment procedures? Why? SPD 320 Topic 1 DQ 2 Have mandated changes in special education eligibility assessment practices had a positive affect for individuals with disabilities and other stakeholders? Why or why not? Cite specific examples. SPD 320 Topic 2 DQ 1 Consider the various informal assessment types commonly used in classroom instruction and identify three you might use regularly in your professional practice. What would those assessments tell you as an educator? Rationalize your choices. SPD 320 Topic 2 DQ 2 Why is understanding basic principles of statistics important as an educator? If you struggle with understanding statistics, what are some problems you might encounter in your professional practi...
Post a Comment
Read more

Committee GCU DNP 960 Topic 3 IRB DPI

Just Click on Below Link To Download This Course: http://bit.ly/2qcN5Sg DNP 960 Topic 3 IRB DPI Committee GCU DNP 960 Topic 3 IRB – DPI-Committee-Approved Proposal Submission You are required to submit your DPI-Committee-Approved DPI Project Proposal to iRIS by the end of this topic.  Note: Learners are required to submit this assignment in full and according to the required instructions no later than Topic 7 of this course. Late submissions after Topic 3 will earn less than full points.  Learners who do not submit this assignment as described by the end of Topic 7 will not pass this course, and will be required to retake DNP-960. General Requirements: Use the following information to assist you in executing the correct procedures for timely, successful completion of the assignment: APA format is required. Prepare this assignment according to the guidelines found in the APA Style Guide, located in the Student Success Center. You are not require...
Post a Comment
Read more

Review the Gleim study units and additional resources assigned as part of this topic.

Just Click on Below Link To Download This Course: https://bit.ly/2ZoNccE ACC 691 TOPIC 1 DQ 1 Review the Gleim study units and additional resources assigned as part of this topic. What questions do you have regarding the content presented? Post your questions to the discussion forum. If you do not have any questions about the material, post something you learned from the reading materials about this topic. Participate in the discussion by responding to the questions and comments of at least three of your peers. ACC 691 TOPIC 1 DQ 2 Within the simulation bank, complete the Gleim simulations for the first of the topic’s assigned study units. There may be up to 10 tasks in each simulation. After you have completed the simulations, post a reply in the forum that your required simulations have been completed. There are no additional postings required. ACC 691 TOPIC 2 DQ 1 Review the Gleim study units and a...
Post a Comment
Read more