Finding the Third Proportional to 5,139 and 12,126

Step by Step Solution

1. Step 1: Write the proportion equation
   5,139 : 12,126 = 12,126 : x
2. Step 2: Convert to fraction form
   5,139/12,126 = 12,126/x
3. Step 3: Cross multiply
   5,139x = 12,126 × 12,126
4. Step 4: Simplify right side
   5,139x = 147,039,876
5. Step 5: Solve for x
   x = 147,039,876/5,139
6. Step 6: Final answer
   x = 28,612.55