Finding the Fourth Proportional to 12,028.16, 18,048.72 and 9,105.76

Step by Step Solution

1. Step 1: Write the proportion equation
   12,028.16 : 18,048.72 = 9,105.76 : x
2. Step 2: Convert to fraction form
   12,028.16/18,048.72 = 9,105.76/x
3. Step 3: Cross multiply
   12,028.16x = 18,048.72 × 9,105.76
4. Step 4: Simplify right side
   12,028.16x = 164,347,312.63
5. Step 5: Solve for x
   x = 164,347,312.63/12,028.16
6. Step 6: Final answer
   x = 13,663.55