Finding the Third Proportional to 309,558 and 677,442

Step by Step Solution

1. Step 1: Write the proportion equation
   309,558 : 677,442 = 677,442 : x
2. Step 2: Convert to fraction form
   309,558/677,442 = 677,442/x
3. Step 3: Cross multiply
   309,558x = 677,442 × 677,442
4. Step 4: Simplify right side
   309,558x = 458,927,663,364
5. Step 5: Solve for x
   x = 458,927,663,364/309,558
6. Step 6: Final answer
   x = 1,482,525.61