Finding the Third Proportional to 121,181.25 and 258,856.50

Step by Step Solution

1. Step 1: Write the proportion equation
   121,181.25 : 258,856.50 = 258,856.50 : x
2. Step 2: Convert to fraction form
   121,181.25/258,856.50 = 258,856.50/x
3. Step 3: Cross multiply
   121,181.25x = 258,856.50 × 258,856.50
4. Step 4: Simplify right side
   121,181.25x = 67,006,687,592.25
5. Step 5: Solve for x
   x = 67,006,687,592.25/121,181.25
6. Step 6: Final answer
   x = 552,946.00