Finding the Fourth Proportional to 13,386.38, 20,076.72 and 8,449.42

Step by Step Solution

1. Step 1: Write the proportion equation
   13,386.38 : 20,076.72 = 8,449.42 : x
2. Step 2: Convert to fraction form
   13,386.38/20,076.72 = 8,449.42/x
3. Step 3: Cross multiply
   13,386.38x = 20,076.72 × 8,449.42
4. Step 4: Simplify right side
   13,386.38x = 169,636,639.50
5. Step 5: Solve for x
   x = 169,636,639.50/13,386.38
6. Step 6: Final answer
   x = 12,672.33