###Human: A storm dropped 5 inches of rain in the first thirty minutes.  In the next 30 minutes, the hurricane dropped half that amount of rain.  It then dropped 1/2 inch of rain for the next hour.  What was the average rainfall total for the duration of the storm?, ### Assistant: The storm dropped 5 inches then half that amount so 5/2 = 2.5 inches
The next hour the storm dropped 1/2 inch of rain for 1 hour so 1*.5 = .5 inches
All total the storm dropped 5 inches + 2.5 inches + .5 inch for = 8 inches
It rained for 2 hours total so 8/2 = 4 inches of rain per hour 
 So the answer is :  4