(2 points) The amount (in milligrams) of a drug in the body 15 hours after taking a pill is given by A(t) = 30(0.89)i . (a) What is the initial dose given? Dose: mg (b) What percent of the drug leaves the body each hour? Percent: (c) What is the amount of drug left after 9 hours? Amount: mg (cl) What is the first whole number of hours at which there is less than 4 milligrams left in the body? Time: hr