Finding the Third Proportional to 431,639 and 677,115.50

Step by Step Solution

1. Step 1: Write the proportion equation
   431,639 : 677,115.50 = 677,115.50 : x
2. Step 2: Convert to fraction form
   431,639/677,115.50 = 677,115.50/x
3. Step 3: Cross multiply
   431,639x = 677,115.50 × 677,115.50
4. Step 4: Simplify right side
   431,639x = 458,485,400,340.25
5. Step 5: Solve for x
   x = 458,485,400,340.25/431,639
6. Step 6: Final answer
   x = 1,062,196.42