Guide to Using Excel For Basic Statistical Applications To Accompany Business Statistics: A Decision Making Approach, 6th Ed. Chapter 9: Hypothesis Testing and Estimation for Two Population Parameters By Groebner, Shannon, Fry, & Smith Prentice-Hall Publishing Company Copyright, 2005

Chapter 9 Excel Examples  Hypothesis Tests – Two Means – Hypothesis Tests – Two Means – SUV Vehicle Mileage  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 Excel to help test the hypothesis for the difference in population means. Data file is Mileage.xls

Hypothesis Test – SUV Vehicle Mileage Open the file on the CD- ROM called Mileage.xls. The null and hypothesis to be test are:

Use Tools – Data Analysis and Descriptive Statistics to calculate statistics from each sample Hypothesis Test – SUV Vehicle Mileage

Define the Input Range and select other features. Hypothesis Test – SUV Vehicle Mileage

Sample Mean, variances and standard deviations for each sample Hypothesis Test – SUV Vehicle Mileage

Use PHStat’s Box and Whisker’s tool to visually test to see whether the normality assumption is satisfied. Define the data range Use Multiple Group – Unstacked to get plots for both city and highway Hypothesis Test – SUV Vehicle Mileage

Resulting Box and Whiskers plots Hypothesis Test – SUV Vehicle Mileage

Use Tools – Data Analysis – t-Test: Two Samples Assuming Equal Variances Hypothesis Test – SUV Vehicle Mileage

Specify data ranges, hypothesized difference = 0.0, and alpha =.05 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. Hypothesis Test – SUV Vehicle Mileage

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

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

Indicate Hypothesized Difference. Enter Sample Size and Number of Occurrences for each population and type of test. Hypothesis Testing – Pomona Manufacturing

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