Finding the Fourth Proportional to 28,570, 42,882.71 and 13,789.33

Step by Step Solution

1. Step 1: Write the proportion equation
   28,570 : 42,882.71 = 13,789.33 : x
2. Step 2: Convert to fraction form
   28,570/42,882.71 = 13,789.33/x
3. Step 3: Cross multiply
   28,570x = 42,882.71 × 13,789.33
4. Step 4: Simplify right side
   28,570x = 591,323,839.48
5. Step 5: Solve for x
   x = 591,323,839.48/28,570
6. Step 6: Final answer
   x = 20,697.37