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_31 (frequency INTEGER, webcast VARCHAR, callsign VARCHAR)
### Question:
Which Frequency has a Webcast of •, and a Callsign of xemr?
### Answer:
SELECT AVG(frequency) FROM table_name_31 WHERE webcast = "•" AND callsign = "xemr"