Finding the Fourth Proportional to 13,687.38, 18,879.89 and 8,971.97

Step by Step Solution

1. Step 1: Write the proportion equation
   13,687.38 : 18,879.89 = 8,971.97 : x
2. Step 2: Convert to fraction form
   13,687.38/18,879.89 = 8,971.97/x
3. Step 3: Cross multiply
   13,687.38x = 18,879.89 × 8,971.97
4. Step 4: Simplify right side
   13,687.38x = 169,389,667.42
5. Step 5: Solve for x
   x = 169,389,667.42/13,687.38
6. Step 6: Final answer
   x = 12,375.61