Finding the Third Proportional to 309,136.50 and 678,051

Step by Step Solution

1. Step 1: Write the proportion equation
   309,136.50 : 678,051 = 678,051 : x
2. Step 2: Convert to fraction form
   309,136.50/678,051 = 678,051/x
3. Step 3: Cross multiply
   309,136.50x = 678,051 × 678,051
4. Step 4: Simplify right side
   309,136.50x = 459,753,158,601
5. Step 5: Solve for x
   x = 459,753,158,601/309,136.50
6. Step 6: Final answer
   x = 1,487,217.33