Finding the Fourth Proportional to 31,139.92, 42,972.78 and 16,992.64

Step by Step Solution

1. Step 1: Write the proportion equation
   31,139.92 : 42,972.78 = 16,992.64 : x
2. Step 2: Convert to fraction form
   31,139.92/42,972.78 = 16,992.64/x
3. Step 3: Cross multiply
   31,139.92x = 42,972.78 × 16,992.64
4. Step 4: Simplify right side
   31,139.92x = 730,220,980.34
5. Step 5: Solve for x
   x = 730,220,980.34/31,139.92
6. Step 6: Final answer
   x = 23,449.67