Finding the Fourth Proportional to 31,139.45, 42,972.22 and 16,991.99

Step by Step Solution

1. Step 1: Write the proportion equation
   31,139.45 : 42,972.22 = 16,991.99 : x
2. Step 2: Convert to fraction form
   31,139.45/42,972.22 = 16,991.99/x
3. Step 3: Cross multiply
   31,139.45x = 42,972.22 × 16,991.99
4. Step 4: Simplify right side
   31,139.45x = 730,183,532.52
5. Step 5: Solve for x
   x = 730,183,532.52/31,139.45
6. Step 6: Final answer
   x = 23,448.83