Finding the Fourth Proportional to 28,105.57, 42,165.15 and 8,385.67

Step by Step Solution

1. Step 1: Write the proportion equation
   28,105.57 : 42,165.15 = 8,385.67 : x
2. Step 2: Convert to fraction form
   28,105.57/42,165.15 = 8,385.67/x
3. Step 3: Cross multiply
   28,105.57x = 42,165.15 × 8,385.67
4. Step 4: Simplify right side
   28,105.57x = 353,583,033.40
5. Step 5: Solve for x
   x = 353,583,033.40/28,105.57
6. Step 6: Final answer
   x = 12,580.53