What is the total population and average area of countries in the continent of North America whose area is bigger than 3000 ?
select sum(population) ,  avg(surfacearea) from country where continent  =  "north america" and surfacearea  >  3000
select sum(population) ,  avg(surfacearea) from country where continent  =  "north america" and surfacearea  >  3000
[{'sum(population)': None, 'avg(surfacearea)': None}]