Is the following situation an example of an observational study, an experiment, or a survey? Explain your answer and provide specific details from the situation that help you to determine which is correct. ~~ A group of eight people work on the fifth floor of the Peyton Building. They all decide they want to lose weight by getting more exercise. Four of them decide to walk up the four flights of stairs each morning. The other four decide to walk down the four flights of stairs at the end of the day. They weigh themselves each Friday morning and compare.