“…x−axis shows the value of the approximation solution, y−axis show the value of α-level values, Y, Y are the lower and upper bounds of the exact solution respectively, y, y are the lower and upper bounds of the approximate solution respectively, E = Y − y computes the absolute error of the lower bound approximation, E = Y − y computes the absolute error of the upper bound approximation, h is the step size, TSBM: Two-step Block Method with Third and Fourth Derivatives, EBHDEF: Extended Block Hybrid Backward Differentiation Formula [16], BDF: Block Differentiation Formula [15], BBDF: Block Backward Differentiation Formula [15], OOMB: Optimization of One-Step Block Method [17], RK5: Runge Kutta Method Order Five [14], OHAM: Optimal Homotopy Asymptotic Method [7], FDM: Finite Difference Method [30].…”