What is average SiO 2, when Na 2 O is 7.53, and when Al 2 O 3 is less than 2.13?
CREATE TABLE table_name_42 (
    sio_2 INTEGER,
    na_2_o VARCHAR,
    al_2_o_3 VARCHAR
)
SELECT AVG(sio_2) FROM table_name_42 WHERE na_2_o = 7.53 AND al_2_o_3 < 2.13
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What is average SiO 2, when Na 2 O is 7.53, and when Al 2 O 3 is less than 2.13? ### Input: CREATE TABLE table_name_42 (
    sio_2 INTEGER,
    na_2_o VARCHAR,
    al_2_o_3 VARCHAR
) ### Response: SELECT AVG(sio_2) FROM table_name_42 WHERE na_2_o = 7.53 AND al_2_o_3 < 2.13