Finding the Third Proportional to 138,499 and 297,688

Step by Step Solution

1. Step 1: Write the proportion equation
   138,499 : 297,688 = 297,688 : x
2. Step 2: Convert to fraction form
   138,499/297,688 = 297,688/x
3. Step 3: Cross multiply
   138,499x = 297,688 × 297,688
4. Step 4: Simplify right side
   138,499x = 88,618,145,344
5. Step 5: Solve for x
   x = 88,618,145,344/138,499
6. Step 6: Final answer
   x = 639,846.82