8 A radioactive material decays according to the function A(t)=Age-0.02441, where Ag is the initial amount present and A is the amount present at time t (in years) Assume that a scientist has a sample of B (a) What is the decay rate of the radioactive material? grams of the radioactive material. (b) Graph the function using a graphing utility. (c) How much radioactive material is left after 20 years? (d) When will only 600 grams of the radioactive material be left? (e) What is the half-life of the radioactive material? (a) The decay rate of the radioactive material is -2.44%. (Type an integer or a decimal.) (b) Graph the function. Choose the correct graph below. The graphing window is [0, 1600, 100] by [0,1,0.25] A. G OB. C. OD. a Q G B