Finding the Fourth Proportional to 31,047.75, 42,839.41 and 20,308.36

Step by Step Solution

1. Step 1: Write the proportion equation
   31,047.75 : 42,839.41 = 20,308.36 : x
2. Step 2: Convert to fraction form
   31,047.75/42,839.41 = 20,308.36/x
3. Step 3: Cross multiply
   31,047.75x = 42,839.41 × 20,308.36
4. Step 4: Simplify right side
   31,047.75x = 869,998,160.47
5. Step 5: Solve for x
   x = 869,998,160.47/31,047.75
6. Step 6: Final answer
   x = 28,021.29