Finding the Fourth Proportional to 20,839.56, 28,750.83 and 13,284.15

Step by Step Solution

1. Step 1: Write the proportion equation
   20,839.56 : 28,750.83 = 13,284.15 : x
2. Step 2: Convert to fraction form
   20,839.56/28,750.83 = 13,284.15/x
3. Step 3: Cross multiply
   20,839.56x = 28,750.83 × 13,284.15
4. Step 4: Simplify right side
   20,839.56x = 381,930,338.34
5. Step 5: Solve for x
   x = 381,930,338.34/20,839.56
6. Step 6: Final answer
   x = 18,327.18