Finding the Third Proportional to 339,540 and 509,350.50

Step by Step Solution

1. Step 1: Write the proportion equation
   339,540 : 509,350.50 = 509,350.50 : x
2. Step 2: Convert to fraction form
   339,540/509,350.50 = 509,350.50/x
3. Step 3: Cross multiply
   339,540x = 509,350.50 × 509,350.50
4. Step 4: Simplify right side
   339,540x = 259,437,931,850.25
5. Step 5: Solve for x
   x = 259,437,931,850.25/339,540
6. Step 6: Final answer
   x = 764,086.50