Using formulas(1.54)through(1.57) we have P1(x)=5-2(x-1 P2(x) (x-1)+0.5(x-1)(x-3) P3(x)=P(x)-0.1(x-1)(x-3)(x-4), P4(x)=B3(x)+0.003(x-1)(x-3)(x-4)(x-45) Evaluating the polynomials at a=2.5 results in P1(25)=5-2(1.5), P2(25)=B(25)+0.5(15)(-0.5)=1.625 P3(25)=P2(25)-0.1(1.5)(-0.5)(-1.5)=1.5125 P4(25)=P3(25)+0.003(1.5)(-0.5)(-1.5)(-2.0)=1.50575