Finding the Third Proportional to 388,129 and 617,185.50

Step by Step Solution

1. Step 1: Write the proportion equation
   388,129 : 617,185.50 = 617,185.50 : x
2. Step 2: Convert to fraction form
   388,129/617,185.50 = 617,185.50/x
3. Step 3: Cross multiply
   388,129x = 617,185.50 × 617,185.50
4. Step 4: Simplify right side
   388,129x = 380,917,941,410.25
5. Step 5: Solve for x
   x = 380,917,941,410.25/388,129
6. Step 6: Final answer
   x = 981,420.97