Chapter PIII, Problem 9RE

To determine

To find: that it is an observational study, sample survey or an experiment and all the parameter of this study and survey and types of conclusions could be reached on the basis of given data.

Explanation of Solution

Researchers have data that long-term exposure contributes to cancer being caused by electromagnetic deposits. This was an observational study.

It was retrospective observational study that means that participants are chosen and prior circumstances and activities determined in this context was that the data obtained from past medical records that can be correlated with increased leukemia rates for people living near the heavy electromagnetic flied. For certain factors associated with socio-economic status, confusing may be responsible for leukemia rates since the neighborhood surrounding the antennas may consist of individuals with the same socio-economic status.