question: What is the name and capacity for the stadium with highest average attendance?
#1 return stadiums 
#2 return attendances of  #1 
#3 return average of  #2 for each  #1 
#4 return #1 where #3 is  highest 
#5 return name of  #4 
#6 return capacity of  #4 
#7 return #5 ,  #6