Finding the Fourth Proportional to 28,380.15, 42,563.39 and 12,576.42

Step by Step Solution

1. Step 1: Write the proportion equation
   28,380.15 : 42,563.39 = 12,576.42 : x
2. Step 2: Convert to fraction form
   28,380.15/42,563.39 = 12,576.42/x
3. Step 3: Cross multiply
   28,380.15x = 42,563.39 × 12,576.42
4. Step 4: Simplify right side
   28,380.15x = 535,295,006.38
5. Step 5: Solve for x
   x = 535,295,006.38/28,380.15
6. Step 6: Final answer
   x = 18,861.60