Finding the Third Proportional to 123,238.50 and 198,411

Step by Step Solution

1. Step 1: Write the proportion equation
   123,238.50 : 198,411 = 198,411 : x
2. Step 2: Convert to fraction form
   123,238.50/198,411 = 198,411/x
3. Step 3: Cross multiply
   123,238.50x = 198,411 × 198,411
4. Step 4: Simplify right side
   123,238.50x = 39,366,924,921
5. Step 5: Solve for x
   x = 39,366,924,921/123,238.50
6. Step 6: Final answer
   x = 319,436.90