Consider a typical disk that rotates at $$15000$$ rotations per minute $$(RPM)$$ and has a transfer rate of $$50 \times {10^6}\,\,\,bytes/\sec .$$ If the average seek time of the disk is twice the average rotational delay and the controller’s transfer time is $$10$$ times the disk transfer time, the average time (in milliseconds) to read or write a $$512$$-byte sector of the disk is ______________________.