Finding the Fourth Proportional to 21,818.72, 30,111.64 and 12,867.96

Step by Step Solution

1. Step 1: Write the proportion equation
   21,818.72 : 30,111.64 = 12,867.96 : x
2. Step 2: Convert to fraction form
   21,818.72/30,111.64 = 12,867.96/x
3. Step 3: Cross multiply
   21,818.72x = 30,111.64 × 12,867.96
4. Step 4: Simplify right side
   21,818.72x = 387,475,379.05
5. Step 5: Solve for x
   x = 387,475,379.05/21,818.72
6. Step 6: Final answer
   x = 17,758.85