Finding the Third Proportional to 239,234.50 and 390,928

Step by Step Solution

1. Step 1: Write the proportion equation
   239,234.50 : 390,928 = 390,928 : x
2. Step 2: Convert to fraction form
   239,234.50/390,928 = 390,928/x
3. Step 3: Cross multiply
   239,234.50x = 390,928 × 390,928
4. Step 4: Simplify right side
   239,234.50x = 152,824,701,184
5. Step 5: Solve for x
   x = 152,824,701,184/239,234.50
6. Step 6: Final answer
   x = 638,807.12