Finding the Third Proportional to 399,494 and 858,280

Step by Step Solution

1. Step 1: Write the proportion equation
   399,494 : 858,280 = 858,280 : x
2. Step 2: Convert to fraction form
   399,494/858,280 = 858,280/x
3. Step 3: Cross multiply
   399,494x = 858,280 × 858,280
4. Step 4: Simplify right side
   399,494x = 736,644,558,400
5. Step 5: Solve for x
   x = 736,644,558,400/399,494
6. Step 6: Final answer
   x = 1,843,943.99