Table schema:
CREATE TABLE table_11647327_2 (marginal_ordinary_income_tax_rate VARCHAR, single VARCHAR)

Question: What is the amount of marginal ordinary income tax rate for single in which the range is $8,351– $33,950?
SQL: SELECT COUNT(marginal_ordinary_income_tax_rate) FROM table_11647327_2 WHERE single = "$8,351– $33,950"