Finding the Fourth Proportional to 13,667.72, 20,508.05 and 8,131.97

Step by Step Solution

1. Step 1: Write the proportion equation
   13,667.72 : 20,508.05 = 8,131.97 : x
2. Step 2: Convert to fraction form
   13,667.72/20,508.05 = 8,131.97/x
3. Step 3: Cross multiply
   13,667.72x = 20,508.05 × 8,131.97
4. Step 4: Simplify right side
   13,667.72x = 166,770,918.96
5. Step 5: Solve for x
   x = 166,770,918.96/13,667.72
6. Step 6: Final answer
   x = 12,201.81