Chapter 8.1, Problem 27E

a)

To determine

To explain whether the study is observational or experimental study.

Answer to Problem 27E

This is an observational study.

Explanation of Solution

Given:

Does living near power lines cause leukemia in children? The National Cancer Institute spent 5 years and S5 million gathering data on this question. The researchers compared 63S children who had leukemia with 620 who did not. They went into the homes and measured the magnetic fields in children's bedrooms, in other rooms, and at the front door. They recorded facts about power lines near the family home and also near the mother's residence when she was pregnant. Result- No association between leukemia and exposure to magnetic fields of the land produced by power lines was found.

First need to understand about the experimental study and observational study:

Experimental study: Assigning people or things to groups and applying some treatment to one group, while the other group does not receive the treatment.

Observation study: In an observational study, measure or survey members of a sample without trying to affect them.

Therefore, in this study, the measurements done by only afterwards. Hence, it is an observational study.

b)

To determine

To explain whether the study proved living near power lines does not cause cancer.

Answer to Problem 27E

No.

Explanation of Solution

Given:

Does living near power lines cause leukemia in children? The National Cancer Institute spent 5 years and S5 million gathering data on this question. The researchers compared 63S children who had leukemia with 620 who did not. They went into the homes and measured the magnetic fields in children's bedrooms, in other rooms, and at the front door. They recorded facts about power lines near the family home and also near the mother's residence when she was pregnant. Result- No association between leukemia and exposure to magnetic fields of the land produced by power lines was found.

This study is an observational study. If we want to prove a cause and effect then the study should be experimental. Because, experimental study will allow to control any variables that could affect the results of the study and that were not included in the study.