Finding the Third Proportional to 217,042.50 and 339,456

Step by Step Solution

1. Step 1: Write the proportion equation
   217,042.50 : 339,456 = 339,456 : x
2. Step 2: Convert to fraction form
   217,042.50/339,456 = 339,456/x
3. Step 3: Cross multiply
   217,042.50x = 339,456 × 339,456
4. Step 4: Simplify right side
   217,042.50x = 115,230,375,936
5. Step 5: Solve for x
   x = 115,230,375,936/217,042.50
6. Step 6: Final answer
   x = 530,911.58