Finding the Third Proportional to 9,921 and 21,386

Step by Step Solution

1. Step 1: Write the proportion equation
   9,921 : 21,386 = 21,386 : x
2. Step 2: Convert to fraction form
   9,921/21,386 = 21,386/x
3. Step 3: Cross multiply
   9,921x = 21,386 × 21,386
4. Step 4: Simplify right side
   9,921x = 457,360,996
5. Step 5: Solve for x
   x = 457,360,996/9,921
6. Step 6: Final answer
   x = 46,100.29