Question 1145936
An inch of rain on an acre of land weighs n amt.  Determine weight.

A cu. ft. of water = 7.5 gal., weighs 62.5 lbs.
1 in. = .083333 ft.
.083333 * 43560 = 3269.985 cu. ft.
3269.985 * 7.5 = 24524.88 gal.
24524.88 * 62.5 = 1532805 lbs. = 766.40  tons 

Where did I miscalculate?
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You used gallons instead of cubic feet.
There's no reason to convert to gallons.