Answer
See below.
Work Step by Step
Pacific: $1.56\cdot10^{14}\cdot4.03\cdot10^3=(1.56\cdot4.03)\cdot(10^{14}\cdot10^3)=6.2868\cdot10^{14+3}=6.2868\cdot10^{17}$
Atlantic: $7.68\cdot10^{13}\cdot3.93\cdot10^3=(7.68\cdot3.93)\cdot(10^{13}\cdot10^3)=30.1824\cdot10^{13+3}=30.1824\cdot10^{16}=3.01824\cdot10^{17}$
Indian: $6.86\cdot10^{13}\cdot3.96\cdot10^3=(6.86\cdot3.96)\cdot(10^{13}\cdot10^3)=27.1656\cdot10^{13+3}=27.1656\cdot10^{16}=2.71656\cdot10^{17}$
Arctic: $1.41\cdot10^{13}\cdot1.21\cdot10^3=(1.41\cdot1.21)\cdot(10^{13}\cdot10^3)=1.7061\cdot10^{13+3}=1.7061\cdot10^{16}$