Table schema:
CREATE TABLE table_22648285_1 (race_time VARCHAR, driver VARCHAR, average_speed__mph_ VARCHAR)

Question: How many races did Cale Yarborough win at an average speed of 88.924 mph?
SQL: SELECT COUNT(race_time) FROM table_22648285_1 WHERE driver = "Cale Yarborough" AND average_speed__mph_ = "88.924"