Finding the Fourth Proportional to 12,158.31, 18,239.35 and 5,138.35

Step by Step Solution

1. Step 1: Write the proportion equation
   12,158.31 : 18,239.35 = 5,138.35 : x
2. Step 2: Convert to fraction form
   12,158.31/18,239.35 = 5,138.35/x
3. Step 3: Cross multiply
   12,158.31x = 18,239.35 × 5,138.35
4. Step 4: Simplify right side
   12,158.31x = 93,720,196.82
5. Step 5: Solve for x
   x = 93,720,196.82/12,158.31
6. Step 6: Final answer
   x = 7,708.33