Guide to Using Excel 2007 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 Excel Examples Hypothesis Tests – Two Means – Hypothesis Tests – Two Means – Hypothesis Tests – Two Means – Hypothesis Tests – Two Means – SUV Vehicle Mileage Hypothesis Testing – Two Proportions - Pomona Fabrications Hypothesis Testing – Two Proportions - Pomona Fabrications Hypothesis Testing – Two Proportions - 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 Excel 2007 to help test the hypothesis for the difference in population means. Data file is Mileage.xls

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

Hypothesis Test – SUV Vehicle Mileage Select the Data tab Select Data Analysis Select Descriptive Statistics OK

Hypothesis Test – SUV Vehicle Mileage Input Range = A1:B26 Note- This range covers BOTH columns Grouped by Columns Labels in First Row New Worksheet Ply – Descriptive Summary Statistics OK

Hypothesis Test – SUV Vehicle Mileage Sample Means, Standard Deviations and Variances are shown for each set of data

Hypothesis Test – SUV Vehicle Mileage Using PHStat’s Box and Whisker tool Set the Cell Range to A1:B26 Select First cell contains label Select Multiple Groups – Unstacked OK

Hypothesis Test – SUV Vehicle Mileage Producing this Box and Whisker Plot

Hypothesis Test – SUV Vehicle Mileage Using the Data Analysis tool, Select t-test Two-Sample Assuming Equal Variances

Hypothesis Test – SUV Vehicle Mileage Variable 1 Range: A1:A26 Variable 2 Range: B1:B26 Hypothesized Mean Difference = 0 Alpha = 0.05 New Worksheet Ply = test

Hypothesis Test – SUV Vehicle Mileage Resulting calculations: p value for one tailed test is.007 which is less than.05 so we reject the null hypothesis.

Issue: The research and development department needs to determine whether the new, redesigned motor-heater is more reliable than the current unit. Objective: Use Excel (PHStat) 2007 to help construct a confidence interval estimate for the difference in population proportions. No data is required for this test. Hypothesis Test – Two Proportions - Pomona Fabrications Hypothesis Test – Two Proportions - Pomona Fabrications

Hypothesis Test – Pomona Fabrications Click on PHStat then Two- Sample Tests then Z Test for Difference in Two Proportions.

Hypothesis Test – Pomona Fabrications Set Hypothesized Difference = 0 Population1 Level of Significance = 0.05 Number of Successes = 55 Sample Size = 250 Population 2 Level of Significance = 0.05 Number of Successes = 75 Sample Size = 250 Lower Tail Test OK

Hypothesis Test – Pomona Fabrications The Lower-Tail test shows that the Null Hypothesis should be rejected