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_15 (call_sign VARCHAR, frequency_mhz VARCHAR, erp_w VARCHAR)
### Question:
Which callsign has ERP W of 99 and a frequency of greater than 88.7MHz?
### Answer:
SELECT call_sign FROM table_name_15 WHERE frequency_mhz > 88.7 AND erp_w = 99