Finding the Third Proportional to 239,499 and 399,148.50

Step by Step Solution

1. Step 1: Write the proportion equation
   239,499 : 399,148.50 = 399,148.50 : x
2. Step 2: Convert to fraction form
   239,499/399,148.50 = 399,148.50/x
3. Step 3: Cross multiply
   239,499x = 399,148.50 × 399,148.50
4. Step 4: Simplify right side
   239,499x = 159,319,525,052.25
5. Step 5: Solve for x
   x = 159,319,525,052.25/239,499
6. Step 6: Final answer
   x = 665,220.00