0C kN/m2 40 1570 220 45 1790 20 240 10 50 2030 30 270 10 55 2030 40 310 60 2610

[ ( ) ( ) ( ) + + ( ) + + ] (f (xo)) etc. A) What is pressure at 75 oC Use Newton’s forward difference formula and extrapolate. 1 2 3 m m m [ ( ) ( ) ( ) Emf(xo) = 1 + + + 1 2 3 4 m ( ) + + etc. ] (f (xo)) 4 Always try to use smallest value of m with largest number of difference values

] (f (xo)) For pressure determination 75 oC we can use 3 difference values if 45 oC is selected as the xo reference ( oC, kN/m2, 2 1 3 , ) (45 , 1790 , 240, 30, 10 ) o 1 2 P75 = [ 1 + (6/1) + (6x5/2x1) 3 ] (f (xo)) + (120/6)

P75 = [ 1 + (6/1)(240) + (15)(30) + (30x4/6)(10) ] (1790) P75 = ( oC, kN/m2, 2 1 3 , ) (75 , , 240, 30, 10 )