Finding the Third Proportional to 414,936 and 640,831.50

Step by Step Solution

1. Step 1: Write the proportion equation
   414,936 : 640,831.50 = 640,831.50 : x
2. Step 2: Convert to fraction form
   414,936/640,831.50 = 640,831.50/x
3. Step 3: Cross multiply
   414,936x = 640,831.50 × 640,831.50
4. Step 4: Simplify right side
   414,936x = 410,665,011,392.25
5. Step 5: Solve for x
   x = 410,665,011,392.25/414,936
6. Step 6: Final answer
   x = 989,706.87