please look at photo

The amount of radioactive material in an ore sample is given by the exponential function A(t) = 400(3.2)", where A(t) is the amount present, in grams, of the sample t months after the initial measurement. How much was present 7 months later? There was/were approximately gram(s) present 7 months later. (Simplify your answer. Type an integer or decimal rounded to the nearest hundredth as needed.)