Algebra 2 Trig Word Problem Help!!!!!!!!!!!!!!! Best answer 10 points rewarded!!!!! Answer all questions!!!!!!?

From 1995 to 2003, the amount of mail M (in billions of pieces) handled by the U.S. Postal service can be modeled by.... M=0.05(t^4 -18t^3+ 89t^2- 32t+3680) where t is the number of years since 1995. In which year (s) was there about 204 billion pieces of mail handled?

a. Write a polynomial equation that can be used to answer the question. (this can only have ONE variable). Then write in standard from with a lead coefficient of 1.

b. Give Domain of the problem

c. Use graphing calculator to graph to determine ALL solutions of the equation.

d. Then list these solutions and write a brief explanation for each solution indicating whether it is a reasonable answer for this situation.