Question

For Hypothesis testing and Decision making problems, please do the following:

1. State the null and alternate hypothesis.

2. Write down the proper test statistic.

3. Show all calculations.

4. Show the critical value.

5. State your conclusions.

2. Some people seem to believe that you can fix anything with duct tape. Even so, many were skeptical when researchers announced that duct tape may be a more effective and less painful alternative to the more traditional technique of using liquid nitrogen to freeze warts. The article “What a Fix-it: Duct Tape Can Remove Warts” (San Luis Obispo Tribune, October 15, 2002) described a study conducted at Madigan Army Medical Center. Patients with warts were randomly assigned to either the duct tape treatment or the more traditional freezing treatment. Those in the duct tape group wore duct tape over the wart for 6 days, then removed the tape, soaked the area in water, and used an emery board to scrape the area. This process was repeated for 2 months or until the wart was gone. Data consistent with values in the article are summarized in the following table:

2a. Test whether there is an association between the type of treatment and whether wart removal was successful.

Treatment

Liquid Nitrogen Freezing Duct Tape Total

Wart Yes 60 88

Removed?   No 40 12

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100 100 200

2b. If the sample size didn’t satisfy size criteria, what statistical test would need to be employed?

Answer 1

2a)

this is chi-square test of independence