Finding the Fourth Proportional to 31,140.78, 42,972.84 and 16,993.32

Step by Step Solution

1. Step 1: Write the proportion equation
   31,140.78 : 42,972.84 = 16,993.32 : x
2. Step 2: Convert to fraction form
   31,140.78/42,972.84 = 16,993.32/x
3. Step 3: Cross multiply
   31,140.78x = 42,972.84 × 16,993.32
4. Step 4: Simplify right side
   31,140.78x = 730,251,221.43
5. Step 5: Solve for x
   x = 730,251,221.43/31,140.78
6. Step 6: Final answer
   x = 23,450.00