5. (20 points total) One problem when you attend an amusement park, especially if the weather is nice, is that you spend a lot of time outside in the sun and end up getting sunburned. Suppose that you have developed a new sunscreen that you would wish to test. Design the experiment in the following two ways:

a) (8 pts) Using a matched pair design.

b) (8 pts) Using a block design, where you choose one confounding variable that you think might influence your results to block with.

c) (4 pts) Which of the designs you proposed would you prefer and why?