Finding the Third Proportional to 309,865.50 and 647,559.56

Step by Step Solution

1. Step 1: Write the proportion equation
   309,865.50 : 647,559.56 = 647,559.56 : x
2. Step 2: Convert to fraction form
   309,865.50/647,559.56 = 647,559.56/x
3. Step 3: Cross multiply
   309,865.50x = 647,559.56 × 647,559.56
4. Step 4: Simplify right side
   309,865.50x = 419,333,386,985.19
5. Step 5: Solve for x
   x = 419,333,386,985.19/309,865.50
6. Step 6: Final answer
   x = 1,353,275.49