Finding the Third Proportional to 399,345 and 868,660.50

Step by Step Solution

1. Step 1: Write the proportion equation
   399,345 : 868,660.50 = 868,660.50 : x
2. Step 2: Convert to fraction form
   399,345/868,660.50 = 868,660.50/x
3. Step 3: Cross multiply
   399,345x = 868,660.50 × 868,660.50
4. Step 4: Simplify right side
   399,345x = 754,571,064,260.25
5. Step 5: Solve for x
   x = 754,571,064,260.25/399,345
6. Step 6: Final answer
   x = 1,889,521.75