Finding the Third Proportional to 338,026.50 and 685,386

Step by Step Solution

1. Step 1: Write the proportion equation
   338,026.50 : 685,386 = 685,386 : x
2. Step 2: Convert to fraction form
   338,026.50/685,386 = 685,386/x
3. Step 3: Cross multiply
   338,026.50x = 685,386 × 685,386
4. Step 4: Simplify right side
   338,026.50x = 469,753,968,996
5. Step 5: Solve for x
   x = 469,753,968,996/338,026.50
6. Step 6: Final answer
   x = 1,389,695.69