Finding the Third Proportional to 9,872 and 21,166

Step by Step Solution

1. Step 1: Write the proportion equation
   9,872 : 21,166 = 21,166 : x
2. Step 2: Convert to fraction form
   9,872/21,166 = 21,166/x
3. Step 3: Cross multiply
   9,872x = 21,166 × 21,166
4. Step 4: Simplify right side
   9,872x = 447,999,556
5. Step 5: Solve for x
   x = 447,999,556/9,872
6. Step 6: Final answer
   x = 45,380.83