Finding the Third Proportional to 3,879,660 and 8,430,768

Step by Step Solution

1. Step 1: Write the proportion equation
   3,879,660 : 8,430,768 = 8,430,768 : x
2. Step 2: Convert to fraction form
   3,879,660/8,430,768 = 8,430,768/x
3. Step 3: Cross multiply
   3,879,660x = 8,430,768 × 8,430,768
4. Step 4: Simplify right side
   3,879,660x = 71,077,849,069,824
5. Step 5: Solve for x
   x = 71,077,849,069,824/3,879,660
6. Step 6: Final answer
   x = 18,320,638.68