Finding the Third Proportional to 4,707,780 and 9,980,505

Step by Step Solution

1. Step 1: Write the proportion equation
   4,707,780 : 9,980,505 = 9,980,505 : x
2. Step 2: Convert to fraction form
   4,707,780/9,980,505 = 9,980,505/x
3. Step 3: Cross multiply
   4,707,780x = 9,980,505 × 9,980,505
4. Step 4: Simplify right side
   4,707,780x = 99,610,480,055,025
5. Step 5: Solve for x
   x = 99,610,480,055,025/4,707,780
6. Step 6: Final answer
   x = 21,158,694.77