Finding the Third Proportional to 399,061.69 and 619,617.09

Step by Step Solution

1. Step 1: Write the proportion equation
   399,061.69 : 619,617.09 = 619,617.09 : x
2. Step 2: Convert to fraction form
   399,061.69/619,617.09 = 619,617.09/x
3. Step 3: Cross multiply
   399,061.69x = 619,617.09 × 619,617.09
4. Step 4: Simplify right side
   399,061.69x = 383,925,342,867.20
5. Step 5: Solve for x
   x = 383,925,342,867.20/399,061.69
6. Step 6: Final answer
   x = 962,070.16