Finding the Fourth Proportional to 31,078.47, 42,891.39 and 18,978.29

Step by Step Solution

1. Step 1: Write the proportion equation
   31,078.47 : 42,891.39 = 18,978.29 : x
2. Step 2: Convert to fraction form
   31,078.47/42,891.39 = 18,978.29/x
3. Step 3: Cross multiply
   31,078.47x = 42,891.39 × 18,978.29
4. Step 4: Simplify right side
   31,078.47x = 814,004,928.57
5. Step 5: Solve for x
   x = 814,004,928.57/31,078.47
6. Step 6: Final answer
   x = 26,191.92