Finding the Fourth Proportional to 31,007.52, 42,810.12 and 20,415.42

Step by Step Solution

1. Step 1: Write the proportion equation
   31,007.52 : 42,810.12 = 20,415.42 : x
2. Step 2: Convert to fraction form
   31,007.52/42,810.12 = 20,415.42/x
3. Step 3: Cross multiply
   31,007.52x = 42,810.12 × 20,415.42
4. Step 4: Simplify right side
   31,007.52x = 873,986,580.05
5. Step 5: Solve for x
   x = 873,986,580.05/31,007.52
6. Step 6: Final answer
   x = 28,186.28