What should Dr. Farquart’s conclusion be?Why do you think 8 people in group B reported feeling better?

Read the following proposed controlled experiments and answer the questions.
Experiment 1: Serious Sandwiches
Dr. Farquart wants to make her home-town a nicer place to live. She has created a new sauce that she predicts will reduce the production of body gas associated with eating sandwiches from the local cafe. She recruits 100 customers with a history of gas problems. She has 50 of them eat sandwiches with the new sauce.
The other 50 eat sandwiches with sauce that looks just like the new sauce but is really only a mixture of mayonnaise and food coloring. Both groups were told that they were eating the sauce that would reduce gas production. Two hours after eating the sandwiches, 30 customers in group A reported having fewer gas problems and 8 customers in group B reported having fewer gas problems.
1. Which group represents the control group?
2. What is the independent variable?
3. What is the dependent variable?
4. What should Dr. Farquart’s conclusion be?
5. Why do you think 8 people in group B reported feeling better?