The storm dropped 5 inches then half that amount so 5/2 = <<5/2=2.5>>2.5 inches
The next hour the storm dropped 1/2 inch of rain for 1 hour so 1*.5 = <<1*.5=.5>>.5 inches
All total the storm dropped 5 inches + 2.5 inches + .5 inch for = <<5+2.5+.5=8>>8 inches
It rained for 2 hours total so 8/2 = <<8/2=4>>4 inches of rain per hour
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