Finding the Fourth Proportional to 12,123.12, 18,165.24 and 10,956.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,123.12 : 18,165.24 = 10,956.72 : x
2. Step 2: Convert to fraction form
   12,123.12/18,165.24 = 10,956.72/x
3. Step 3: Cross multiply
   12,123.12x = 18,165.24 × 10,956.72
4. Step 4: Simplify right side
   12,123.12x = 199,031,448.41
5. Step 5: Solve for x
   x = 199,031,448.41/12,123.12
6. Step 6: Final answer
   x = 16,417.51