Finding the Third Proportional to 138,499.50 and 297,689

Step by Step Solution

1. Step 1: Write the proportion equation
   138,499.50 : 297,689 = 297,689 : x
2. Step 2: Convert to fraction form
   138,499.50/297,689 = 297,689/x
3. Step 3: Cross multiply
   138,499.50x = 297,689 × 297,689
4. Step 4: Simplify right side
   138,499.50x = 88,618,740,721
5. Step 5: Solve for x
   x = 88,618,740,721/138,499.50
6. Step 6: Final answer
   x = 639,848.81