Finding the Fourth Proportional to 31,056.28, 42,807.82 and 20,981.48

Step by Step Solution

1. Step 1: Write the proportion equation
   31,056.28 : 42,807.82 = 20,981.48 : x
2. Step 2: Convert to fraction form
   31,056.28/42,807.82 = 20,981.48/x
3. Step 3: Cross multiply
   31,056.28x = 42,807.82 × 20,981.48
4. Step 4: Simplify right side
   31,056.28x = 898,171,419.17
5. Step 5: Solve for x
   x = 898,171,419.17/31,056.28
6. Step 6: Final answer
   x = 28,920.77