In 4 weeks, it dropped 3 feet in total.
The unit rate of this is 3 feet / 4 weeks
If we simplify this into days, this will be the solutions
=> 4 weeks has (4 * 7) 28 days in total, so we need to divide 3 feet by 28 days to get the simplified unit rate.
=> 3 feet / 28 days
=> .107 feet / day.
So the water drops .107 feet per day and in 4 weeks the total of 3 feet.