Take the distance in miles (1.5) and divide by the time in hours. Since 12 minutes is .2 hours, you would divide 1.5 by .2 to get 7.5 mph.
If your goal is a 11 min. mile and a half, your mile time should be about 7:33.
It matters how much you want to run.
Practice and training. The record for a mile is less than 4 minutes, so half a mile should be easy.
7.5 mph
The pace to run a half mile in 4 minutes 13 seconds is 7.12 (7.11462451) miles per hour.
I think if you are a fast runner I think you should sprint half and jog half your last mile.
5.625 (= 55/8) miles per hour.
8 minutes
8-10 minutes, probably.
About 7.9 minutes per mile.
Faster
from 2 and half minutes to 3 minutes.