Well, you start with 300 meters per 30.2 second, the first thing you do is change that to x meters per 1 second. which is around 10 (actually 9.93377). Then you change meters to miles. OK so there are 1609.344 meters in a mile (or 1/1609.344 miles/meter), so you have 10 meters/second * (1/1609.344 miles per meter) so you end up with 10/1609.344 miles/second. Now we need to change seconds to hours, one second is 1/60 minutes which is 1/60 hours. So 1 second is 1/3600 hours (or 1 hour is 3600 seconds). So we have 10/1609.344 miles/second * 3600 seconds/hour we end up with 10 * 3600/1609.344 miles/hour which is a little over 22 miles per hour.