Jenny wants to determine if a new brand name washing detergent is better than her old detergent. she washes ten dirty t-shirts with the new washing detergent and ten dirty t-shirts with the old detergent. identify the dependent and independent variables for this experiment. don't forget both the iv and dv in your answer!

When a vertical beam of light passes through a transparent medium, the rate at which its intensity i decreases is proportional to i(t), where t represents the thickness of the medium (in feet). in clear seawater, the intensity 3 feet below the surface is 25% of the initial intensity i0 of the incident beam. what is the intensity of the beam "10" feet below the surface? (give your answer in terms of i0. round any constants or coefficients to five decimal places.)