Ijust can't seem to get the my T = 679 when Length = 1. Using step size L of 1.

My k1, k2, k3, k4 are:

k1, k2, k3, k4 = 1*(0.65267*-3712900.595*706*56791.1128/555.87*47.65) = -8.365*10^12

T1 = 673 + 1/6*(-8.365*10^12 + 2(-8.365*10^12) + 2(-8.365*10^12) + (-8.365*10^12)) = -8.365*10^12

this clearly isn't 679 so pls help. If the differential equation i use to find my k1, k2, k3, k4, can show how to derive the correct one and redo everything again.

=0.652670905HR=3729033.595kJ/molRNH3=56791.1128kmol/m3.hrA=706m2FTotal=555.87kmol/hrCpmix=47.65kJ/kmol.KT(0)=673L(0)=0 Question: Solve dLdT=FTotalCpmix(HR)ARNH3 using 4th order Runge Kutta method and plot a Temperature (T) vs Length (L) graph using Excel. Please show a detailed working of which values were used how to get the k1,k2k3 and k4 values using Length =1 as the example. Also provide Excel sheet if possible. Note: Please show how to derive the differential equation used for the 4th order Runge Kutta method and what each cell A,B,C, etc. in Excel means too. Answer: =0.652670905HR=3729033.595kJ/molRNH3=56791.1128kmol/m3.hrA=706m2FTotal=555.87kmol/hrCpmix=47.65kJ/kmol.KT(0)=673L(0)=0 Question: Solve dLdT=FTotalCpmix(HR)ARNH3 using 4th order Runge Kutta method and plot a Temperature (T) vs Length (L) graph using Excel. Please show a detailed working of which values were used how to get the k1,k2k3 and k4 values using Length =1 as the example. Also provide Excel sheet if possible. Note: Please show how to derive the differential equation used for the 4th order Runge Kutta method and what each cell A,B,C, etc. in Excel means too