Finding the Third Proportional to 316,446 and 644,641.50

Step by Step Solution

1. Step 1: Write the proportion equation
   316,446 : 644,641.50 = 644,641.50 : x
2. Step 2: Convert to fraction form
   316,446/644,641.50 = 644,641.50/x
3. Step 3: Cross multiply
   316,446x = 644,641.50 × 644,641.50
4. Step 4: Simplify right side
   316,446x = 415,562,663,522.25
5. Step 5: Solve for x
   x = 415,562,663,522.25/316,446
6. Step 6: Final answer
   x = 1,313,218.25