Finding the Third Proportional to 425,385 and 638,077.50

Step by Step Solution

1. Step 1: Write the proportion equation
   425,385 : 638,077.50 = 638,077.50 : x
2. Step 2: Convert to fraction form
   425,385/638,077.50 = 638,077.50/x
3. Step 3: Cross multiply
   425,385x = 638,077.50 × 638,077.50
4. Step 4: Simplify right side
   425,385x = 407,142,896,006.25
5. Step 5: Solve for x
   x = 407,142,896,006.25/425,385
6. Step 6: Final answer
   x = 957,116.25