Finding the Fourth Proportional to 13,153.89, 18,157.57 and 8,120.15

Step by Step Solution

1. Step 1: Write the proportion equation
   13,153.89 : 18,157.57 = 8,120.15 : x
2. Step 2: Convert to fraction form
   13,153.89/18,157.57 = 8,120.15/x
3. Step 3: Cross multiply
   13,153.89x = 18,157.57 × 8,120.15
4. Step 4: Simplify right side
   13,153.89x = 147,442,149.04
5. Step 5: Solve for x
   x = 147,442,149.04/13,153.89
6. Step 6: Final answer
   x = 11,209.01