Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What is the entry for Lower index MJ/ Nm 3 for the row that has an Upper index Kcal/ Nm 3 larger than 19,376, for lpg, and an Upper index MJ/ Nm 3 smaller than 86.84?

### Inputs:
table_name: table, columns: ['Fuel gas', 'Upper index Kcal/ Nm 3', 'Lower index Kcal/ Nm 3', 'Upper index MJ/ Nm 3', 'Lower index MJ/ Nm 3']

### Response:
SELECT AVG Lower index MJ/ Nm 3 FROM table WHERE Upper index Kcal/ Nm 3 > 19,376 AND Fuel gas = lpg AND Upper index MJ/ Nm 3 < 86.84