Finding the Third Proportional to 8,398 and 19,870

Step by Step Solution

1. Step 1: Write the proportion equation
   8,398 : 19,870 = 19,870 : x
2. Step 2: Convert to fraction form
   8,398/19,870 = 19,870/x
3. Step 3: Cross multiply
   8,398x = 19,870 × 19,870
4. Step 4: Simplify right side
   8,398x = 394,816,900
5. Step 5: Solve for x
   x = 394,816,900/8,398
6. Step 6: Final answer
   x = 47,013.21