Finding the Fourth Proportional to 31,139.02, 42,972.29 and 16,991.76

Step by Step Solution

1. Step 1: Write the proportion equation
   31,139.02 : 42,972.29 = 16,991.76 : x
2. Step 2: Convert to fraction form
   31,139.02/42,972.29 = 16,991.76/x
3. Step 3: Cross multiply
   31,139.02x = 42,972.29 × 16,991.76
4. Step 4: Simplify right side
   31,139.02x = 730,174,838.33
5. Step 5: Solve for x
   x = 730,174,838.33/31,139.02
6. Step 6: Final answer
   x = 23,448.87