Finding the Third Proportional to 289,440 and 445,153.50

Step by Step Solution

1. Step 1: Write the proportion equation
   289,440 : 445,153.50 = 445,153.50 : x
2. Step 2: Convert to fraction form
   289,440/445,153.50 = 445,153.50/x
3. Step 3: Cross multiply
   289,440x = 445,153.50 × 445,153.50
4. Step 4: Simplify right side
   289,440x = 198,161,638,562.25
5. Step 5: Solve for x
   x = 198,161,638,562.25/289,440
6. Step 6: Final answer
   x = 684,638.05