Finding the Fourth Proportional to 31,488.16, 47,236.56 and 13,957.60

Step by Step Solution

1. Step 1: Write the proportion equation
   31,488.16 : 47,236.56 = 13,957.60 : x
2. Step 2: Convert to fraction form
   31,488.16/47,236.56 = 13,957.60/x
3. Step 3: Cross multiply
   31,488.16x = 47,236.56 × 13,957.60
4. Step 4: Simplify right side
   31,488.16x = 659,309,009.86
5. Step 5: Solve for x
   x = 659,309,009.86/31,488.16
6. Step 6: Final answer
   x = 20,938.31