Finding the Third Proportional to 258,128 and 553,623.50

Step by Step Solution

1. Step 1: Write the proportion equation
   258,128 : 553,623.50 = 553,623.50 : x
2. Step 2: Convert to fraction form
   258,128/553,623.50 = 553,623.50/x
3. Step 3: Cross multiply
   258,128x = 553,623.50 × 553,623.50
4. Step 4: Simplify right side
   258,128x = 306,498,979,752.25
5. Step 5: Solve for x
   x = 306,498,979,752.25/258,128
6. Step 6: Final answer
   x = 1,187,391.45