Finding the Third Proportional to 12,858 and 20,955

Step by Step Solution

1. Step 1: Write the proportion equation
   12,858 : 20,955 = 20,955 : x
2. Step 2: Convert to fraction form
   12,858/20,955 = 20,955/x
3. Step 3: Cross multiply
   12,858x = 20,955 × 20,955
4. Step 4: Simplify right side
   12,858x = 439,112,025
5. Step 5: Solve for x
   x = 439,112,025/12,858
6. Step 6: Final answer
   x = 34,150.88