Balance and fitness

You are doing research on balance and fitness. To complete this research you will need a watch with a second
hand. Identify a random sample of n = 12 men and n = 8 women. You must answer this question: How do you
establish that this sample is truly random?
Have each subject perform the following task:
a) Have the subjects stand with their hands at their side, raise one knee, cross their ankle over the other knee,
squat and bring their hands palms together in front of their chest. Time the subject until they put their foot back
down on the floor.
b) Ask the following questions:
i) How many days per week do they exercise?
ii) What is their favorite exercise?