can i get some help with this

4. It is believed by many people that the Macintosh Operating System (OS 10) is superior to that of Windows because it is much more intuitive. Experimenters decide to test this conjecture. They take a sample of 72 computer users each claiming to have experience with both operating systems. They give them a series of tasks to do on each computer platform and record the amount of time it takes to complete the tasks in total. Design a completely randomized experiment that would test the theory. Then design an experiment where the experimenters block for the user's level of computer expertise (a little, medium, expert). Finally, outline a matched pairs design where each subjects acts as his/her own control