Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_38 (erp_w VARCHAR, call_sign VARCHAR)
### Question:
If the call sign is w291ch what's the ERP W corresponding to that sign?
### Answer:
SELECT erp_w FROM table_name_38 WHERE call_sign = "w291ch"