Finding the Third Proportional to 258,142.50 and 379,616.50

Step by Step Solution

1. Step 1: Write the proportion equation
   258,142.50 : 379,616.50 = 379,616.50 : x
2. Step 2: Convert to fraction form
   258,142.50/379,616.50 = 379,616.50/x
3. Step 3: Cross multiply
   258,142.50x = 379,616.50 × 379,616.50
4. Step 4: Simplify right side
   258,142.50x = 144,108,687,072.25
5. Step 5: Solve for x
   x = 144,108,687,072.25/258,142.50
6. Step 6: Final answer
   x = 558,252.47