Finding the Third Proportional to 308,512 and 641,648

Step by Step Solution

1. Step 1: Write the proportion equation
   308,512 : 641,648 = 641,648 : x
2. Step 2: Convert to fraction form
   308,512/641,648 = 641,648/x
3. Step 3: Cross multiply
   308,512x = 641,648 × 641,648
4. Step 4: Simplify right side
   308,512x = 411,712,155,904
5. Step 5: Solve for x
   x = 411,712,155,904/308,512
6. Step 6: Final answer
   x = 1,334,509.37