Finding the Third Proportional to 239,488.50 and 399,132

Step by Step Solution

1. Step 1: Write the proportion equation
   239,488.50 : 399,132 = 399,132 : x
2. Step 2: Convert to fraction form
   239,488.50/399,132 = 399,132/x
3. Step 3: Cross multiply
   239,488.50x = 399,132 × 399,132
4. Step 4: Simplify right side
   239,488.50x = 159,306,353,424
5. Step 5: Solve for x
   x = 159,306,353,424/239,488.50
6. Step 6: Final answer
   x = 665,194.17