Finding the Third Proportional to 418,003.50 and 640,498.88

Step by Step Solution

1. Step 1: Write the proportion equation
   418,003.50 : 640,498.88 = 640,498.88 : x
2. Step 2: Convert to fraction form
   418,003.50/640,498.88 = 640,498.88/x
3. Step 3: Cross multiply
   418,003.50x = 640,498.88 × 640,498.88
4. Step 4: Simplify right side
   418,003.50x = 410,238,808,876.27
5. Step 5: Solve for x
   x = 410,238,808,876.27/418,003.50
6. Step 6: Final answer
   x = 981,424.34