Finding the Third Proportional to 407,494 and 645,105

Step by Step Solution

1. Step 1: Write the proportion equation
   407,494 : 645,105 = 645,105 : x
2. Step 2: Convert to fraction form
   407,494/645,105 = 645,105/x
3. Step 3: Cross multiply
   407,494x = 645,105 × 645,105
4. Step 4: Simplify right side
   407,494x = 416,160,461,025
5. Step 5: Solve for x
   x = 416,160,461,025/407,494
6. Step 6: Final answer
   x = 1,021,267.70