Indicate whether the study is an observational study or a controlled experiment. A researcher was interested in the effects of exercise on academic performance in elementary school children. She went to the recess area of an elementary school and identified some students who were exercising vigorously and some who were not. The researcher then compared the grades of the exercisers with the grades of those who did not exercise.

The study is  an observational study.      

Explanation:

Observational study: In psychological research, the term "observational study" is described as a non-experimental yet empirical investigation associated with the effects that are being caused by a specific treatment. In other words, an observational study is determined as a study in which inferences is being drawn from a specific sample related to a particular population where an independent variable is not considered as under the control of the investigator due to logical constraints and ethical concerns.

In the question above, the given statement represents an observational study.

the arab empire adopted the muslim religion as their main belief. arabs would influence the people from the territories they invaded towards islam (the muslim belief).

nevertheless, throughout the history of the arab empire, rulers brought intellectual individuals from other religions to their centers of learning. these other foreigners included jews, christians, greeks, persians, and indians.   these resulted in the adoption of important knowledge developed by these cultures by the arabic empire. for example, the works of aristotle were translated from greek to arab and indian scientists brought the numerical concept of "zero" to the arabs.

nowadays, 93% of the arab population is muslim, which at the same time is subdivided in sects including the sunni, zaini, alawi, shia. the remaining 7% is composed mainly of christians.

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explanation:

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