Finding the Third Proportional to 404,959.50 and 640,426.50

Step by Step Solution

1. Step 1: Write the proportion equation
   404,959.50 : 640,426.50 = 640,426.50 : x
2. Step 2: Convert to fraction form
   404,959.50/640,426.50 = 640,426.50/x
3. Step 3: Cross multiply
   404,959.50x = 640,426.50 × 640,426.50
4. Step 4: Simplify right side
   404,959.50x = 410,146,101,902.25
5. Step 5: Solve for x
   x = 410,146,101,902.25/404,959.50
6. Step 6: Final answer
   x = 1,012,807.71