a conical cup is 4 \text{ cm} across and 8 \text{ cm} deep. water leaks out of the bottom at the rate of 3 \textrm{ cm}^3/\textrm{s}. what is the rate of change of the water's level when the height of the water is 4 \text{ cm}? please enter your answer in decimal format with three significant digits after the decimal point.
