Finding the Fourth Proportional to 31,078.48, 42,888.20 and 16,931.28

Step by Step Solution

1. Step 1: Write the proportion equation
   31,078.48 : 42,888.20 = 16,931.28 : x
2. Step 2: Convert to fraction form
   31,078.48/42,888.20 = 16,931.28/x
3. Step 3: Cross multiply
   31,078.48x = 42,888.20 × 16,931.28
4. Step 4: Simplify right side
   31,078.48x = 726,152,122.90
5. Step 5: Solve for x
   x = 726,152,122.90/31,078.48
6. Step 6: Final answer
   x = 23,365.11