Finding the Third Proportional to 320,806,591 and 687,655,404

Step by Step Solution

1. Step 1: Write the proportion equation
   320,806,591 : 687,655,404 = 687,655,404 : x
2. Step 2: Convert to fraction form
   320,806,591/687,655,404 = 687,655,404/x
3. Step 3: Cross multiply
   320,806,591x = 687,655,404 × 687,655,404
4. Step 4: Simplify right side
   320,806,591x = 472,869,954,650,403,200
5. Step 5: Solve for x
   x = 472,869,954,650,403,200/320,806,591
6. Step 6: Final answer
   x = 1,474,003,240.32