Finding the Fourth Proportional to 21,057.28, 31,589.04 and 7,012.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,057.28 : 31,589.04 = 7,012.72 : x
2. Step 2: Convert to fraction form
   21,057.28/31,589.04 = 7,012.72/x
3. Step 3: Cross multiply
   21,057.28x = 31,589.04 × 7,012.72
4. Step 4: Simplify right side
   21,057.28x = 221,525,092.59
5. Step 5: Solve for x
   x = 221,525,092.59/21,057.28
6. Step 6: Final answer
   x = 10,520.12