Finding the Third Proportional to 138,418.50 and 213,469.50

Step by Step Solution

1. Step 1: Write the proportion equation
   138,418.50 : 213,469.50 = 213,469.50 : x
2. Step 2: Convert to fraction form
   138,418.50/213,469.50 = 213,469.50/x
3. Step 3: Cross multiply
   138,418.50x = 213,469.50 × 213,469.50
4. Step 4: Simplify right side
   138,418.50x = 45,569,227,430.25
5. Step 5: Solve for x
   x = 45,569,227,430.25/138,418.50
6. Step 6: Final answer
   x = 329,213.42