Finding the Third Proportional to 9,898 and 21,780

Step by Step Solution

1. Step 1: Write the proportion equation
   9,898 : 21,780 = 21,780 : x
2. Step 2: Convert to fraction form
   9,898/21,780 = 21,780/x
3. Step 3: Cross multiply
   9,898x = 21,780 × 21,780
4. Step 4: Simplify right side
   9,898x = 474,368,400
5. Step 5: Solve for x
   x = 474,368,400/9,898
6. Step 6: Final answer
   x = 47,925.68