Finding the Third Proportional to 138,798 and 298,644

Step by Step Solution

1. Step 1: Write the proportion equation
   138,798 : 298,644 = 298,644 : x
2. Step 2: Convert to fraction form
   138,798/298,644 = 298,644/x
3. Step 3: Cross multiply
   138,798x = 298,644 × 298,644
4. Step 4: Simplify right side
   138,798x = 89,188,238,736
5. Step 5: Solve for x
   x = 89,188,238,736/138,798
6. Step 6: Final answer
   x = 642,575.82