Finding the Third Proportional to 9,138 and 12,891

Step by Step Solution

1. Step 1: Write the proportion equation
   9,138 : 12,891 = 12,891 : x
2. Step 2: Convert to fraction form
   9,138/12,891 = 12,891/x
3. Step 3: Cross multiply
   9,138x = 12,891 × 12,891
4. Step 4: Simplify right side
   9,138x = 166,177,881
5. Step 5: Solve for x
   x = 166,177,881/9,138
6. Step 6: Final answer
   x = 18,185.37