Guide to Using Minitab 14 For Basic Statistical Applications To Accompany Business Statistics: A Decision Making Approach, 8th Ed. Chapter 14: Introduction to Linear Regression and Correlation Analysis By Groebner, Shannon, Fry, & Smith Prentice-Hall Publishing Company Copyright, 2011

Chapter 14 Minitab Examples Correlation Analysis Correlation Analysis Correlation Analysis Correlation Analysis Midwest Distribution Regression Analysis Regression Analysis Regression Analysis Regression Analysis Fitzpatrick and Associates Fitzpatrick and Associates Simple Linear Regression Analysis Simple Linear Regression Analysis Simple Linear Regression Analysis Simple Linear Regression AnalysisVantage Regression Analysis for Decision-Making Regression Analysis for Decision-Making Regression Analysis for Decision-Making Regression Analysis for Decision-Making Car Mileage Regression Analysis for Prediction Regression Analysis for Prediction Regression Analysis for Prediction Regression Analysis for Prediction Freedom Hospital Residual Analysis Residual Analysis Residual Analysis Residual Analysis Freedom Hospital

Correlation Analysis - Midwest Distribution Issue: The company wants to analyze the relationship between salary and years with the company. Objective: Use Minitab to help test whether a significant relations exists between salary and years with the company. Data file is Midwest.MTW

Open File Midwest.MTW Correlation Analysis – Midwest Distribution.

Click on Graph – Scatterplot Correlation Analysis – Midwest Distribution.

Select Simple Correlation Analysis – Midwest Distribution.

Identify Y and X variables, click OK Correlation Analysis – Midwest Distribution.

Scatterplot shows a positive linear relationship. Correlation Analysis – Midwest Distribution.

First click on Stat, then Basic Statistics and finally on Correlation. Correlation Analysis – Midwest Distribution

Identify the columns containing the data to be analyzed. Click on OK Correlation Analysis – Midwest Distribution

The Minitab output shows the correlation between Sales and Years with Midwest. Correlation Analysis – Midwest Distribution

Regression Analysis Fitzpatrick & Associates. Issue: The Fitzpatrick analysts want to model the relationship between profits and number of employees. Objective: Use Minitab to test whether the apparent linear relationship is statistically significant. Data file is Fortune 50.MTW

Open File Fortune 50.MTW Regression Analysis – Fitzpatrick & Associates

Click on Graph button, then Scatterplot Regression Analysis – Fitzpatrick & Associates

Select Simple Regression Analysis – Fitzpatrick & Associates

Identify the columns containing the variables to be graphed. Regression Analysis – Fitzpatrick & Associates

Minitab provides the scatter plot. Regression Analysis – Fitzpatrick & Associates

Click on Stat, then Regression and Regression again. Regression Analysis – Fitzpatrick & Associates

Identify the columns containing values of Profits (Response) and Employees (Predictors). Click on OK Regression Analysis – Fitzpatrick & Associates

The output shows the R- square value and the regression equation. Regression Analysis – Fitzpatrick & Associates

Simple Linear Regression Analysis - Vantage Electronic Systems Issue: The R&D Department at Vantage wishes to determine if knowing the Vantage visibility reading provides useful help in knowing what its Scorpion sensor’s visibility reading will be. Objective: Use Minitab to determine the significance of a simple linear regression model using the Vantage visibility measure to predict the Scorpion measure. Data file is Vantage.MTW

Open File Vantage.MTW File contains data for 280 sensor readings. Simple Linear Regression Analysis – Vantage

Click on Stat, then Regression and Regression again. Simple Linear Regression Analysis – Vantage

Identify the columns containing values of Scorpion Visibility (Response) and Vantage Visibility(Predictors) Simple Linear Regression Analysis – Vantage

Test statistic and p- value to test the hypothesis that the slope equals 0 Simple Linear Regression Analysis – Vantage

Regression Analysis for Decision-Making - Car Mileage Issue: Analysts at a major automobile company were interested in establishing the relationship between horsepower and highway mileage. Initially, they wished to determine how much the average miles per gallon will decrease if the horsepower of a randomly selected automobile were to be increased by one horsepower. Objective: Use Minitab to develop a range of plausible miles per gallon resulting from an increase of one horsepower of an automobile’s engine. Data file is Automobiles.MTW

Open File Automobiles.MTW Regression Analysis for Decision-Making – Car Mileage

Click on Stat, then Regression and Regression again. Regression Analysis for Decision-Making – Car Mileage

Identify the columns containing values of Highway mileage (Response) and Horsepower (Predictor). Regression Analysis for Decision-Making – Car Mileage

Test statistic and p- value to test the hypothesis that the slope equals 0

Regression Analysis for Prediciton - Freedom Hospital Issue: The administrator has been requested by the hospital’s board of directors to develop a model that can be used to predict the total charges for a geriatric patient, as an example, a five-day stay. Objective: Use Minitab to develop a statistically significant prediction model. Data file is Patients.MTW

Open File Patients.MTW File contains data for 138 patients. Regression Analysis for Prediction – Freedom Hospital

Click on Stat, then Regression and Regression again. Regression Analysis for Prediction – Freedom Hospital

Identify the columns containing values of Total Charges (Response) and Length of Stay (Predictors) and finally Options. Regression Analysis for Prediction – Freedom Hospital

Specify value of x used to predict the y variable – specify confidence level. Click OK Regression Analysis for Prediction – Freedom Hospital

95% prediction interval Regression Analysis for Prediction – Freedom Hospital