Finding the Third Proportional to 11,138 and 20,818

Step by Step Solution

1. Step 1: Write the proportion equation
   11,138 : 20,818 = 20,818 : x
2. Step 2: Convert to fraction form
   11,138/20,818 = 20,818/x
3. Step 3: Cross multiply
   11,138x = 20,818 × 20,818
4. Step 4: Simplify right side
   11,138x = 433,389,124
5. Step 5: Solve for x
   x = 433,389,124/11,138
6. Step 6: Final answer
   x = 38,910.86