Finding the Fourth Proportional to 28,508.50, 42,771.98 and 13,715.50

Step by Step Solution

1. Step 1: Write the proportion equation
   28,508.50 : 42,771.98 = 13,715.50 : x
2. Step 2: Convert to fraction form
   28,508.50/42,771.98 = 13,715.50/x
3. Step 3: Cross multiply
   28,508.50x = 42,771.98 × 13,715.50
4. Step 4: Simplify right side
   28,508.50x = 586,639,091.69
5. Step 5: Solve for x
   x = 586,639,091.69/28,508.50
6. Step 6: Final answer
   x = 20,577.69