Finding the Fourth Proportional to 31,663.94, 47,478.38 and 12,957.12

Step by Step Solution

1. Step 1: Write the proportion equation
   31,663.94 : 47,478.38 = 12,957.12 : x
2. Step 2: Convert to fraction form
   31,663.94/47,478.38 = 12,957.12/x
3. Step 3: Cross multiply
   31,663.94x = 47,478.38 × 12,957.12
4. Step 4: Simplify right side
   31,663.94x = 615,183,002.28
5. Step 5: Solve for x
   x = 615,183,002.28/31,663.94
6. Step 6: Final answer
   x = 19,428.51