(D)(E) T(4) = ( 1.62 + 2(4.15) + 2(7.5) + 2(9.0) + 12.13 ).(B) , using a graphing calculator. (D)(E) T(4) = ( 1.62 + 2(4.15) + 2(7.5) + 2(9.0) + 12.13 ).(B) , using a graphing calculator.