Finding the Fourth Proportional to 31,078.97, 42,892.08 and 18,978.79

Step by Step Solution

1. Step 1: Write the proportion equation
   31,078.97 : 42,892.08 = 18,978.79 : x
2. Step 2: Convert to fraction form
   31,078.97/42,892.08 = 18,978.79/x
3. Step 3: Cross multiply
   31,078.97x = 42,892.08 × 18,978.79
4. Step 4: Simplify right side
   31,078.97x = 814,039,469.63
5. Step 5: Solve for x
   x = 814,039,469.63/31,078.97
6. Step 6: Final answer
   x = 26,192.61