Finding the Third Proportional to 399,519 and 858,328.50

Step by Step Solution

1. Step 1: Write the proportion equation
   399,519 : 858,328.50 = 858,328.50 : x
2. Step 2: Convert to fraction form
   399,519/858,328.50 = 858,328.50/x
3. Step 3: Cross multiply
   399,519x = 858,328.50 × 858,328.50
4. Step 4: Simplify right side
   399,519x = 736,727,813,912.25
5. Step 5: Solve for x
   x = 736,727,813,912.25/399,519
6. Step 6: Final answer
   x = 1,844,036.99