Finding the Third Proportional to 307,689 and 664,585.50

Step by Step Solution

1. Step 1: Write the proportion equation
   307,689 : 664,585.50 = 664,585.50 : x
2. Step 2: Convert to fraction form
   307,689/664,585.50 = 664,585.50/x
3. Step 3: Cross multiply
   307,689x = 664,585.50 × 664,585.50
4. Step 4: Simplify right side
   307,689x = 441,673,886,810.25
5. Step 5: Solve for x
   x = 441,673,886,810.25/307,689
6. Step 6: Final answer
   x = 1,435,455.56