A random sample of 400 small to midrange (non-luxury) condominiums sold in Vancouver last year shows prices ranging from 700,000 to 1,900,000. A histogram of the selling prices is approximately normally distributed. A reasonable estimate of the standard deviation of the selling prices is ________. (Select the best answer)
1) 10,000
2) 100,000
3) 200,000
4) 300,000
5) Cannot be determined from the given information