Finding the Fourth Proportional to 12,712.88, 18,991.72 and 10,118.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,712.88 : 18,991.72 = 10,118.72 : x
2. Step 2: Convert to fraction form
   12,712.88/18,991.72 = 10,118.72/x
3. Step 3: Cross multiply
   12,712.88x = 18,991.72 × 10,118.72
4. Step 4: Simplify right side
   12,712.88x = 192,171,897.00
5. Step 5: Solve for x
   x = 192,171,897.00/12,712.88
6. Step 6: Final answer
   x = 15,116.31