Finding the Fourth Proportional to 13,180.61, 18,188.80 and 7,872.27

Step by Step Solution

1. Step 1: Write the proportion equation
   13,180.61 : 18,188.80 = 7,872.27 : x
2. Step 2: Convert to fraction form
   13,180.61/18,188.80 = 7,872.27/x
3. Step 3: Cross multiply
   13,180.61x = 18,188.80 × 7,872.27
4. Step 4: Simplify right side
   13,180.61x = 143,187,144.58
5. Step 5: Solve for x
   x = 143,187,144.58/13,180.61
6. Step 6: Final answer
   x = 10,863.47