Finding the Fourth Proportional to 31,057.10, 42,815.73 and 20,969.56

Step by Step Solution

1. Step 1: Write the proportion equation
   31,057.10 : 42,815.73 = 20,969.56 : x
2. Step 2: Convert to fraction form
   31,057.10/42,815.73 = 20,969.56/x
3. Step 3: Cross multiply
   31,057.10x = 42,815.73 × 20,969.56
4. Step 4: Simplify right side
   31,057.10x = 897,827,019.18
5. Step 5: Solve for x
   x = 897,827,019.18/31,057.10
6. Step 6: Final answer
   x = 28,908.91