which situation is an example of an observational study?\na. asking voters about the candidate they…

which situation is an example of an observational study?\na. asking voters about the candidate they prefer\nb. testing the effectiveness of a new reading program by allowing a classroom to use it and comparing the results with another classroom that doesnt use it\nc. having customers who bought a certain type of car answer questions about their satisfaction with the car\nd. measuring the weights of patients who come for a check - up in a hospital

which situation is an example of an observational study?\na. asking voters about the candidate they prefer\nb. testing the effectiveness of a new reading program by allowing a classroom to use it and comparing the results with another classroom that doesnt use it\nc. having customers who bought a certain type of car answer questions about their satisfaction with the car\nd. measuring the weights of patients who come for a check - up in a hospital

Answer

Brief Explanations:

An observational study just observes and records data without interfering. Option A is a survey, B is an experiment (has treatment and control groups), C is a survey about satisfaction. Option D just measures weights of patients without any intervention, which is an observational study.

Answer:

D. Measuring the weights of patients who come for a check - up in a hospital