Finding the Third Proportional to 320,564 and 685,600

Step by Step Solution

1. Step 1: Write the proportion equation
   320,564 : 685,600 = 685,600 : x
2. Step 2: Convert to fraction form
   320,564/685,600 = 685,600/x
3. Step 3: Cross multiply
   320,564x = 685,600 × 685,600
4. Step 4: Simplify right side
   320,564x = 470,047,360,000
5. Step 5: Solve for x
   x = 470,047,360,000/320,564
6. Step 6: Final answer
   x = 1,466,313.62