Finding the Third Proportional to 258,128.25 and 553,624.50

Step by Step Solution

1. Step 1: Write the proportion equation
   258,128.25 : 553,624.50 = 553,624.50 : x
2. Step 2: Convert to fraction form
   258,128.25/553,624.50 = 553,624.50/x
3. Step 3: Cross multiply
   258,128.25x = 553,624.50 × 553,624.50
4. Step 4: Simplify right side
   258,128.25x = 306,500,087,000.25
5. Step 5: Solve for x
   x = 306,500,087,000.25/258,128.25
6. Step 6: Final answer
   x = 1,187,394.59