Finding the Third Proportional to 315,730 and 676,388

Step by Step Solution

1. Step 1: Write the proportion equation
   315,730 : 676,388 = 676,388 : x
2. Step 2: Convert to fraction form
   315,730/676,388 = 676,388/x
3. Step 3: Cross multiply
   315,730x = 676,388 × 676,388
4. Step 4: Simplify right side
   315,730x = 457,500,726,544
5. Step 5: Solve for x
   x = 457,500,726,544/315,730
6. Step 6: Final answer
   x = 1,449,025.20