Scientists interested in the effect of exercise on the duration of sleep conducted the following study: 180 overweight men were
randomly assigned to two groups. One group was instructed to perform aerobic exercise for about an hour per day, and the other group was instructed to continue with their exercise-less routine. The sleep duration of each subject was measured at two points: before the randomization and 101010 weeks after it. Then, the scientists calculated the change in sleep duration for each subject, where a positive value means the duration increased, and a negative value means is decreased.
What type of statistical study did scientists use?
'Experimental study' is characterized as the study pattern in which the researchers deliberately involve intervention or manipulation in the treatment group to observe its effect.
As per the given details, the scientists have employed an '<u>experimental research</u>' pattern because the research group was divided into two groups 'control group' and 'experimental group' where the experimental group receives an intervention('instructed to continue with their exercise-less routine'). Then the results of the two groups were observed, examined, and analyzed. Hence, it exemplifies the 'experimental research' type.
The best option is D studied. This word denotes a measured, even-handed approach to the issue. So, it should be :Current immigration policy must be studied before new proposals can be made.
