Finding the Third Proportional to 12,381 and 21,858

Step by Step Solution

1. Step 1: Write the proportion equation
   12,381 : 21,858 = 21,858 : x
2. Step 2: Convert to fraction form
   12,381/21,858 = 21,858/x
3. Step 3: Cross multiply
   12,381x = 21,858 × 21,858
4. Step 4: Simplify right side
   12,381x = 477,772,164
5. Step 5: Solve for x
   x = 477,772,164/12,381
6. Step 6: Final answer
   x = 38,589.14