Finding the Fourth Proportional to 31,139.28, 42,970.77 and 16,991.82

Step by Step Solution

1. Step 1: Write the proportion equation
   31,139.28 : 42,970.77 = 16,991.82 : x
2. Step 2: Convert to fraction form
   31,139.28/42,970.77 = 16,991.82/x
3. Step 3: Cross multiply
   31,139.28x = 42,970.77 × 16,991.82
4. Step 4: Simplify right side
   31,139.28x = 730,151,589.10
5. Step 5: Solve for x
   x = 730,151,589.10/31,139.28
6. Step 6: Final answer
   x = 23,447.93