Question 698394
To answer this question you:
1st know He surveys 200 members and that the median number is the middle of the data once set in order.  
so the adults could of said: 
2 hours,4,6,8,10.... and so forth.
This statement is misleading because median is only the middle of the data once set in order so its not the averaged person that exercises 10 hours per week it's just one person that ended up in the middle everyone's might be different. He just picked the median from the set of digits.