Finding the Fourth Proportional to 11,666.30, 16,099.81 and 7,129.71

Step by Step Solution

1. Step 1: Write the proportion equation
   11,666.30 : 16,099.81 = 7,129.71 : x
2. Step 2: Convert to fraction form
   11,666.30/16,099.81 = 7,129.71/x
3. Step 3: Cross multiply
   11,666.30x = 16,099.81 × 7,129.71
4. Step 4: Simplify right side
   11,666.30x = 114,786,976.36
5. Step 5: Solve for x
   x = 114,786,976.36/11,666.30
6. Step 6: Final answer
   x = 9,839.20