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Course Documents

Chapter 1 - Intro

Chapter 2 - Methods for Describing Sets of Data

Chapter 3 - Probability

Chapter 4 - Discrete Random Variables

Chapter 5 - Normal Random Variables

Chapter 6 - Sampling Distributions

Chapter 7 - Confidence Intervals

Chapter 8 - Tests of Hypothesis: One Sample

Chapter 9 - Confidence Intervals and Hypothesis Tests: Two Samples

Sample Exam I: Chapters 1 & 2

Sample Exam II: Chapters 3 & 4

Sample Exam III: Chapters 5 & 6

Sample Exam IV: Chapters 7 & 8

Problem 1

Clothing manufacturers use a wear-testing machine to measure different fabrics’ ability to withstand abrasion. The wear of the material is measured by weighing the clothing after it has been through the wear-testing machine. A manufacturer wants to determine if there is a difference between the average weight loss among four different materials. The experiment is done by using four samples of each kind of material. The samples were tested in a completely randomized order. The weights are listed below. Use the data below and a 1% significance level to construct an ANOVA table and to determine if at least one fabric is significantly different from the others.

           Fabric
   A        B      C      D
1.93 2.55 2.40 2.33
2.38 2.72 2.68 2.40
2.20 2.75 2.31 2.28
2.25 2.70 2.28 2.25

 

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