The frequency of an fm radio station is 89.3 mhz. calculate its period.

The period of any wave is  1 / (its frequency).

89.3 MHz means  89.3 million per second

1 / (89.3 million per second)  =  1.12 x 10⁻⁸ second.

That's 0.0000000112 second.

0.0112 microsecond

11.2 nanoseconds