Strontium 90 is a radioactive material that decays according to the function A(t)=A_{0} e^{-0.0244 t},A(t)=A
0 e −0.0244t, where A_{0}A 0 is the initial amount present and A is the amount present at time t (in years). Assume that a scientist has a sample of 800 grams of strontium 90. What is the decay rate of strontium 90?