Finding the Fourth Proportional to 12,155.64, 18,236.42 and 5,131.87

Step by Step Solution

1. Step 1: Write the proportion equation
   12,155.64 : 18,236.42 = 5,131.87 : x
2. Step 2: Convert to fraction form
   12,155.64/18,236.42 = 5,131.87/x
3. Step 3: Cross multiply
   12,155.64x = 18,236.42 × 5,131.87
4. Step 4: Simplify right side
   12,155.64x = 93,586,936.71
5. Step 5: Solve for x
   x = 93,586,936.71/12,155.64
6. Step 6: Final answer
   x = 7,699.05