Finding the Third Proportional to 312,672 and 636,386

Step by Step Solution

1. Step 1: Write the proportion equation
   312,672 : 636,386 = 636,386 : x
2. Step 2: Convert to fraction form
   312,672/636,386 = 636,386/x
3. Step 3: Cross multiply
   312,672x = 636,386 × 636,386
4. Step 4: Simplify right side
   312,672x = 404,987,140,996
5. Step 5: Solve for x
   x = 404,987,140,996/312,672
6. Step 6: Final answer
   x = 1,295,245.95