Question

You are conducting a study on the health of people who have been exposed to radiation and those who have not been exposed to radiation. Which of these methods of obtaining data should you most likely adopt and why?
a. an observational study because it involves the pre-existing condition of the subjects
b. an experimental study because it will give the most accurate results
c. an experimental study because results can be obtained much faster using this technique
d. a sample survey with only people who were not exposed to radiation because it involves random selection
e. a sample survey with only people who were exposed to radiation because it involves random selection

Answer 1

Answer:

a. an observational study because it involves the pre-existing condition of the subjects

Step-by-step explanation:

Given that You are conducting a study on the health of people who have been exposed to radiation and those who have not been exposed to radiation.

Already some people exposed to radiation and not exposed is being taken for sample.

Hence here no change is made so it is only an observational study and not experimental study.

Option e, d are incorrect sinc both groups must be observed.

Option b and c are incorrect because this is not an experimental study.

Hence correct option is

a. an observational study because it involves the pre-existing condition of the subjects

Answer 2

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The best and most correct answer among the choices provided by the question is a. an observational study because it involves the pre-existing condition of the subjects.    
      
Hope my answer would be a great help for you.