Table: fuel_gas_wobbe
Columns: fuel_gas
upper_index_kcal_nm_3
lower_index_kcal_nm_3
upper_index_mj_nm_3
lower_index_mj_nm_3

Question: What is the Upper index Kcal/ Nm 3 of iso-butane, and a Lower index MJ/ Nm 3 smaller than 84.71?
SQL: SELECT COUNT("upper_index_kcal_nm_3") FROM fuel_gas_wobbe WHERE "fuel_gas" = 'iso-butane' AND "lower_index_mj_nm_3" < 84.71

Question: What is the entry for Upper index Kcal/ Nm 3 for the row with an entry that has a Lower index MJ/ Nm 3 of 47.91, and an Upper index MJ/ Nm 3 larger than 53.28?
SQL: SELECT SUM("upper_index_kcal_nm_3") FROM fuel_gas_wobbe WHERE "lower_index_mj_nm_3" = 47.91 AND "upper_index_mj_nm_3" > 53.28

Question: What is the entry for Upper index Kcal/ Nm 3 for the row with an entry that has a Lower index MJ/ Nm 3 larger than 47.91, for propylene, and an Upper index MJ/ Nm 3 larger than 77.04?
SQL: SELECT SUM("upper_index_kcal_nm_3") FROM fuel_gas_wobbe WHERE "lower_index_mj_nm_3" > 47.91 AND "fuel_gas" = 'propylene' AND "upper_index_mj_nm_3" > 77.04