Finding the Third Proportional to 404,966 and 640,435

Step by Step Solution

1. Step 1: Write the proportion equation
   404,966 : 640,435 = 640,435 : x
2. Step 2: Convert to fraction form
   404,966/640,435 = 640,435/x
3. Step 3: Cross multiply
   404,966x = 640,435 × 640,435
4. Step 4: Simplify right side
   404,966x = 410,156,989,225
5. Step 5: Solve for x
   x = 410,156,989,225/404,966
6. Step 6: Final answer
   x = 1,012,818.33