Table: glass_chemistry
Columns: objects
date
sio_2
al_2_o_3
fe_2_o_3
k_2_o
na_2_o

Question: What is average SiO 2, when Na 2 O is 7.53, and when Al 2 O 3 is less than 2.13?
SQL: SELECT AVG("sio_2") FROM glass_chemistry WHERE "na_2_o" = 7.53 AND "al_2_o_3" < 2.13

Question: What is the highest K 2 O, when Na 2 O is greater than 1.87, when Fe 2 O 3 is greater than 0.07, when Objects is Ritual Disk, and when Al 2 O 3 is less than 0.62?
SQL: SELECT MAX("k_2_o") FROM glass_chemistry WHERE "na_2_o" > 1.87 AND "fe_2_o_3" > 0.07 AND "objects" = 'ritual disk' AND "al_2_o_3" < 0.62

Question: What is the highest SiO 2, when K 2 O is greater than 0.16, when Fe 2 O 3 is greater than 0.16, and when Na 2 O is less than 7.53?
SQL: SELECT MAX("sio_2") FROM glass_chemistry WHERE "k_2_o" > 0.16 AND "fe_2_o_3" > 0.16 AND "na_2_o" < 7.53