Give the total population and average surface area corresponding to countries in North America that have a surface area greater 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}]