Finding the Fourth Proportional to 21,086.79, 29,099.46 and 11,655.15

Step by Step Solution

1. Step 1: Write the proportion equation
   21,086.79 : 29,099.46 = 11,655.15 : x
2. Step 2: Convert to fraction form
   21,086.79/29,099.46 = 11,655.15/x
3. Step 3: Cross multiply
   21,086.79x = 29,099.46 × 11,655.15
4. Step 4: Simplify right side
   21,086.79x = 339,158,571.22
5. Step 5: Solve for x
   x = 339,158,571.22/21,086.79
6. Step 6: Final answer
   x = 16,083.94