Finding the Third Proportional to 426,807 and 639,103.50

Step by Step Solution

1. Step 1: Write the proportion equation
   426,807 : 639,103.50 = 639,103.50 : x
2. Step 2: Convert to fraction form
   426,807/639,103.50 = 639,103.50/x
3. Step 3: Cross multiply
   426,807x = 639,103.50 × 639,103.50
4. Step 4: Simplify right side
   426,807x = 408,453,283,712.25
5. Step 5: Solve for x
   x = 408,453,283,712.25/426,807
6. Step 6: Final answer
   x = 956,997.62