Guide to Using Minitab 14 For Basic Statistical Applications To Accompany Business Statistics: A Decision Making Approach, 8th Ed. Chapter 10: Estimation and Hypothesis Testing for Two Population Parameters By Groebner, Shannon, Fry, & Smith Prentice-Hall Publishing Company Copyright, 2011

Chapter 10 Minitab Examples ä Hypothesis Tests – Two Means Hypothesis Tests – Two Means SUV Mileage ä Hypothesis Testing – Two Proportions Pomona Fabrications Hypothesis Testing – Two Proportions

Hypothesis Test – Two Means SUV Vehicle Mileage Hypothesis Test – Two Means SUV Vehicle Mileage Issue: A national car rental agency wishes to test whether SUV vehicles have different mean city mileage versus highway mileage. The premise is that mean highway mileage will exceed mean city mileage Objective: Use Minitab to help test the hypothesis for the difference in population means. Data file is Mileage.MTW

Hypothesis Test – SUV Vehicle Mileage Open the file Mileage.MTW. The null and alternative hypothesis to be tested are:

After clicking on Graph, select Boxplot for visual check of normality assumptions Hypothesis Test – SUV Vehicle Mileage

Select Multiple Y’s - Simple Hypothesis Test – SUV Vehicle Mileage

Select variables to graph Hypothesis Test – SUV Vehicle Mileage

Resulting Boxplots Hypothesis Test – SUV Vehicle Mileage

Go to Stat, click on Basic Statistics, then 2-Sample t Hypothesis Test – SUV Vehicle Mileage

Specify variables for analysis and check Assume equal variances, then click on Options Hypothesis Test – SUV Vehicle Mileage

Specify confidence level, hypothesized mean, and form of the alternative Hypothesis Test – SUV Vehicle Mileage

Hypothesis Test results. Since t-value = 2.52 is associated with a p-value of 0.007, reject the null hypothesis Hypothesis Test – SUV Vehicle Mileage

Issue: The research and development department needs to determine whether the new, redesigned motor-heater is more reliable than the current unit. Objective: Use Minitab to help conduct a hypothesis test about the difference between two population proportions. No data is required for this test. Hypothesis Testing – Two Proportions - Pomona Manufacturing

Click on Stat – then Basic Statistics – then 2 Proportions. Hypothesis Testing – Pomona Manufacturing

Choose Summarized data, enter Sample Size and Number of Successes for each population. Click on options. Hypothesis Testing – Pomona Manufacturing

Indicate the Confidence Level (1- α), the Hypothesized Difference, and the alternative hypothesis. Hypothesis Testing – Pomona Manufacturing Check “Use Pooled estimate….

The Lower Tail Test shows the null hypothesis should be rejected. Hypothesis Testing – Pomona Manufacturing