Finding the Fourth Proportional to 12,131.80, 18,183.30 and 5,111.80

Step by Step Solution

1. Step 1: Write the proportion equation
   12,131.80 : 18,183.30 = 5,111.80 : x
2. Step 2: Convert to fraction form
   12,131.80/18,183.30 = 5,111.80/x
3. Step 3: Cross multiply
   12,131.80x = 18,183.30 × 5,111.80
4. Step 4: Simplify right side
   12,131.80x = 92,949,392.94
5. Step 5: Solve for x
   x = 92,949,392.94/12,131.80
6. Step 6: Final answer
   x = 7,661.63