please it's reservoir engineering question from tarek ahmed. please the already existing solutions are wrong so please kindly read carefully and solve

3. A 0.7 specific gravity gas is flowing in a linear reservoir system at 150F. The upstream and downstream pressures are 2,000 and 1.800 psi, respectively. The system has the following properties: L=2000ftk=40mdW0=15%=300ft Calculate the gas flow rate