It usually takes me between 7-10 Minutes to walk 0.4 miles

The normal speed for an individual to walk a mile varies from 5 miles to 8 miles an hour. If we take an average of 6 miles per hour, that means for 0.4 miles it will take approx. 5 minutes.

5-8 miles an hour is running speed.

Depends on your speed. Average walking speed is 2 to 3 mph. You do the math.