Finding the Fourth Proportional to 13,142.81, 18,156.86 and 8,616.25

Step by Step Solution

1. Step 1: Write the proportion equation
   13,142.81 : 18,156.86 = 8,616.25 : x
2. Step 2: Convert to fraction form
   13,142.81/18,156.86 = 8,616.25/x
3. Step 3: Cross multiply
   13,142.81x = 18,156.86 × 8,616.25
4. Step 4: Simplify right side
   13,142.81x = 156,443,975.73
5. Step 5: Solve for x
   x = 156,443,975.73/13,142.81
6. Step 6: Final answer
   x = 11,903.39