Finding the Third Proportional to 399,081.75 and 619,607.69

Step by Step Solution

1. Step 1: Write the proportion equation
   399,081.75 : 619,607.69 = 619,607.69 : x
2. Step 2: Convert to fraction form
   399,081.75/619,607.69 = 619,607.69/x
3. Step 3: Cross multiply
   399,081.75x = 619,607.69 × 619,607.69
4. Step 4: Simplify right side
   399,081.75x = 383,913,686,409.10
5. Step 5: Solve for x
   x = 383,913,686,409.10/399,081.75
6. Step 6: Final answer
   x = 961,992.59