Finding the Third Proportional to 421,606.50 and 553,536

Step by Step Solution

1. Step 1: Write the proportion equation
   421,606.50 : 553,536 = 553,536 : x
2. Step 2: Convert to fraction form
   421,606.50/553,536 = 553,536/x
3. Step 3: Cross multiply
   421,606.50x = 553,536 × 553,536
4. Step 4: Simplify right side
   421,606.50x = 306,402,103,296
5. Step 5: Solve for x
   x = 306,402,103,296/421,606.50
6. Step 6: Final answer
   x = 726,749.00