In a survey of 2,500 U. S. adults, 68% responded that they were confident that "smart homes" will be as commonplace as smartphones within 10 years.† Indicate whether the study is an observational study or an experiment. Give a brief explanation for your choice. (Hint: See Examples 1.2 and 1.3.) This is an experiment because the adults were assigned to different experimental groups and then the researchers recorded responses to questions on a survey. This is an observational study because the researchers recorded responses to questions on a survey. No adults were assigned to different experimental groups. This is an experiment because the researchers conducted a survey. Adults were randomly selected for the survey. This is an observational study because the researchers observed how many of the 2,500 adults have smartphones.