Finding the Fourth Proportional to 31,115, 42,939.78 and 17,686.82

Step by Step Solution

1. Step 1: Write the proportion equation
   31,115 : 42,939.78 = 17,686.82 : x
2. Step 2: Convert to fraction form
   31,115/42,939.78 = 17,686.82/x
3. Step 3: Cross multiply
   31,115x = 42,939.78 × 17,686.82
4. Step 4: Simplify right side
   31,115x = 759,468,159.70
5. Step 5: Solve for x
   x = 759,468,159.70/31,115
6. Step 6: Final answer
   x = 24,408.43