Finding the Third Proportional to 111,138.75 and 242,689.50

Step by Step Solution

1. Step 1: Write the proportion equation
   111,138.75 : 242,689.50 = 242,689.50 : x
2. Step 2: Convert to fraction form
   111,138.75/242,689.50 = 242,689.50/x
3. Step 3: Cross multiply
   111,138.75x = 242,689.50 × 242,689.50
4. Step 4: Simplify right side
   111,138.75x = 58,898,193,410.25
5. Step 5: Solve for x
   x = 58,898,193,410.25/111,138.75
6. Step 6: Final answer
   x = 529,951.92