Physics conversion problem

Mr. Johnson walks at a pace of 7 mph. What is his speed in meters per second? Please show work if you can. The "per hour" and "per second" is throwing me off here. Thanks!

7 mph = (7 miles) /(1 hour) = (7*1609 meters)( 3600 seconds = 3.13 m/s

(7 x 1.6093) = 11.2651kph.
(11.2651/3.6) = 3.13 metres/sec. (3.129194444).

1 mile = 1609.34 meters
1 hours = 60 * 60 = 3600 sec

7 mph = 7*1609.34/3600 = 11265.38/3600 = 3.13 mps (meter per second)

7 mph -----> m= mile???? (1 mile = 1609 m)
7mph = 7 * 1609/3600 = 3.13 meters/sec