Finding the Third Proportional to 3,879,639 and 8,430,804

Step by Step Solution

1. Step 1: Write the proportion equation
   3,879,639 : 8,430,804 = 8,430,804 : x
2. Step 2: Convert to fraction form
   3,879,639/8,430,804 = 8,430,804/x
3. Step 3: Cross multiply
   3,879,639x = 8,430,804 × 8,430,804
4. Step 4: Simplify right side
   3,879,639x = 71,078,456,086,416
5. Step 5: Solve for x
   x = 71,078,456,086,416/3,879,639
6. Step 6: Final answer
   x = 18,320,894.31